diff --git a/CHANGELOG b/CHANGELOG
index 4d83c4a..7d224cc 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,9 +1,17 @@
+0.6.5
+- Sessions are now autosaved every 60s (#97)
+- Bugfixes:
+  - Loading of sessions with hierarchy children failed (#99)
+  - Reduced a memory leak for new analyses that resulted in frequent
+    memory errors (should be less frequent now)
 0.6.4
 - Bugfixes:
   - Batch analysis: Individual measurement parameters not preserved (#96)
   - Legend plot: >9 measurements cannot be displayed in legend at
     the same time. Introduced new config key "Legend Autoscaled" (#91) 
 - New filter hierarchy allows to investigate subpopulations (#87, #63)
+- dclab
+  - Add InertiaRatio and InertiaRatioRaw to tdms files (typo)
 0.6.3
 - Bugfixes:
   - Regression: Excluded events plotted on top of filtered events (#86)
diff --git a/appveyor.yml b/appveyor.yml
index 83411af..25c87aa 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -6,7 +6,8 @@
 
 # Do not use shallow_clone, because coveralls needs a git repository
 #shallow_clone: true
-clone_depth: 10
+# Use large clone depth so that a tag is included for versioning
+clone_depth: 256
 
 
 # Only build master branch
@@ -86,6 +87,7 @@ install:
   # https://ci.appveyor.com/project/paulmueller/shapeout/build/1.0.152#L504
   - "pip freeze"
   # PIP installs
+  - "pip install appdirs"
   - "pip install nptdms"
   # install pyper (R)
   - "pip install pyper"
diff --git a/requirements.txt b/requirements.txt
index eef18a4..bb79707 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,4 @@
+appdirs
 chaco>=4.1.0
 cffi>=0.8.2
 dclab>=0.1.0
diff --git a/setup.py b/setup.py
index 592b862..9de7308 100644
--- a/setup.py
+++ b/setup.py
@@ -43,7 +43,7 @@
             'GUI':  ["wxPython", "chaco", "opencv"],
             # kiwisolver?
         },
-        install_requires=["dclab", "NumPy>=1.7.0", "SciPy>=0.10.0",
+        install_requires=["appdirs", "dclab", "NumPy>=1.7.0", "SciPy>=0.10.0",
                           "pyper"],
         setup_requires=['pytest-runner'],
         tests_require=["pytest", "urllib3"],
diff --git a/shapeout/ShapeOut.py b/shapeout/ShapeOut.py
index 5865ae5..656daf2 100644
--- a/shapeout/ShapeOut.py
+++ b/shapeout/ShapeOut.py
@@ -32,6 +32,7 @@ def main():
     # close the splash screen
     splash.terminate()
     # launch application
+    app.frame.InitRun()
     app.MainLoop()
     
     
diff --git a/shapeout/__main__.py b/shapeout/__main__.py
index 7fa6e5f..106c362 100644
--- a/shapeout/__main__.py
+++ b/shapeout/__main__.py
@@ -58,19 +58,20 @@ def prepare_app():
         warnings.warn(_("Could not determine ShapeOut version."))
         version = None
     
+    app.frame = frontend.Frame(version)
+    
+    return app
+
+if __name__ == "__main__":
     # get session file
     session_file = None
     for arg in sys.argv:
         if arg.endswith(".zmso"):
-            print("\nLoading Session "+arg)
+            print("\nUsing Session "+arg)
             session_file=arg
         else:
             print("Ignoring command line parameter: "+arg)
 
-    app.frame = frontend.Frame(version, session_file=session_file)
-    
-    return app
-
-if __name__ == "__main__":
     app = prepare_app()
+    app.frame.InitRun(session_file=session_file)
     app.MainLoop()
diff --git a/shapeout/analysis.py b/shapeout/analysis.py
index 8f334a2..dce6e1b 100644
--- a/shapeout/analysis.py
+++ b/shapeout/analysis.py
@@ -11,6 +11,7 @@
 import copy
 import numpy as np
 import os
+import sys
 import warnings
 
 # dclab imports
@@ -53,6 +54,41 @@ def __init__(self, data, search_path="./"):
                              " .tdms files: {}".format(data))
 
 
+    def _clear(self):
+        """Remove all attributes from this instance, making it unusable
+        
+        It is difficult to control how the chaco plots refer to a measurement
+        object.
+        
+        """
+        import gc
+        for _i in range(len(self.measurements)):
+            mm = self.measurements.pop(0)
+            # Deleting all the data in measurements!
+            attrs = dclab.definitions.rdv
+            attrs += ["_filter_"+a for a in attrs]
+            attrs += ["_filter", "_plot_filter", "_Downsampled_Scatter"]
+            for a in attrs:
+                if hasattr(mm, a):
+                    b = getattr(mm, a)
+                    del b
+            # Also delete fluorescence curves
+            for tr in list(mm.traces.keys()):
+                t = mm.traces.pop(tr)
+                del t
+            del mm.traces
+            refs = gc.get_referrers(mm)
+            for r in refs:
+                if hasattr(r, "delplot"):
+                    r.delplot()
+                    import IPython
+                    IPython.embed()
+                del r
+            del mm
+        dclab.cached.Cache.clear_cache()
+        gc.collect()
+
+
     def _ImportDumped(self, indexname, search_path="./"):
         """ Loads data from index file as saved using `self.DumpData`.
         
@@ -96,8 +132,12 @@ def _ImportDumped(self, indexname, search_path="./"):
                     ids = [mm.identifier for mm in measmts if mm is not None]
                     mms = [mm for mm in measmts if mm is not None]
                     if idhp in ids:
+                        # parent exists
                         hparent = mms[ids.index(idhp)]  
                         mm = RTDC_DataSet(hparent=hparent)
+                    else:
+                        # parent doesn't exist - try again in next loop
+                        continue
                 else:
                     tloc = session_get_tdms_file(data, search_path)
                     mm = RTDC_DataSet(tloc)
@@ -195,9 +235,8 @@ def DumpData(self, directory, fullout=False, rel_path="./"):
         for i in range(len(out)):
             out[i] += "\r\n"
         
-        index = codecs.open(indexname, "w", "utf-8")
-        index.writelines(out)
-        index.close()
+        with codecs.open(indexname, "w", "utf-8") as index:
+            index.writelines(out)
         
         # Dump polygons
         if len(PolygonFilter.instances) > 0:
diff --git a/shapeout/gui/autosave.py b/shapeout/gui/autosave.py
new file mode 100644
index 0000000..a3d9f13
--- /dev/null
+++ b/shapeout/gui/autosave.py
@@ -0,0 +1,77 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+""" ShapeOut - autosaving of sessions
+"""
+from __future__ import division, print_function
+
+import appdirs
+import os
+import time
+import wx
+import wx.lib.delayedresult as delayedresult
+
+from . import session
+
+cache_dir = appdirs.user_cache_dir(appname="ShapeOut")
+autosave_file = os.path.join(cache_dir, "autosave.zmso")
+
+
+def mkdir_p(adir):
+    """Recursively create a directory"""
+    adir = os.path.abspath(adir)
+    while not os.path.exists(adir):
+        try:
+            os.mkdir(adir)
+        except:
+            mkdir_p(os.path.dirname(adir))
+
+
+def _autosave_consumer(delayedresult, parent):
+    parent.StatusBar.SetStatusText("Autosaving...")
+    tempname = autosave_file+".tmp"
+    mkdir_p(cache_dir)
+    try:
+        session.save_session(tempname, parent.analysis)
+    except:
+        parent.StatusBar.SetStatusText("Autosaving failed!")
+        if os.path.exists(tempname):
+            os.remove(tempname)
+    else:
+        if os.path.exists(autosave_file):
+            os.remove(autosave_file)
+        os.rename(tempname, autosave_file)
+        parent.StatusBar.SetStatusText("")
+    autosave_run(parent)
+
+
+def _autosave_worker(parent, interval):
+    """Runs in the background and performs autosaving"""
+    time.sleep(interval)
+
+
+def autosave_run(parent, interval=60):
+    """Runs in the background and performs autosaving"""
+    delayedresult.startWorker(_autosave_consumer,
+                              _autosave_worker,
+                              wargs=(parent, interval,),
+                              cargs=(parent,))
+
+
+def check_recover(parent):
+    """Check for a recovery file and ask if user wants to restore
+    
+    Returns True if a session was restored. False otherwise.
+    """
+    if os.path.exists(autosave_file):
+        message="Autosaved session found. Restore?"
+        dlg = wx.MessageDialog(parent,
+                               caption=_("Missing tdms files for session"),
+                               message=message,
+                               style=wx.YES|wx.NO,
+                               )
+        mod = dlg.ShowModal()
+        dlg.Destroy()
+        if mod == wx.ID_YES:
+            session.open_session(autosave_file, parent)
+            return True
+    return False
diff --git a/shapeout/gui/frontend.py b/shapeout/gui/frontend.py
index 9ddf49b..d5450d2 100644
--- a/shapeout/gui/frontend.py
+++ b/shapeout/gui/frontend.py
@@ -11,12 +11,9 @@
 import numpy as np
 import os
 import platform
-import shutil
 import sys
-import tempfile
 import traceback
 import wx
-import zipfile
 
 import dclab
 
@@ -27,6 +24,7 @@
 import gaugeframe
 from .. import analysis
 from .. import tlabwrap
+from . import autosave
 from . import update
 from . import plot_main
 from . import misc
@@ -34,6 +32,8 @@
 from . import export
 from . import batch
 from . import plot_export
+from . import session
+
 
 ########################################################################
 class ExceptionDialog(wx.MessageDialog):
@@ -47,7 +47,7 @@ def __init__(self, msg):
 ########################################################################
 class Frame(gaugeframe.GaugeFrame):
     """"""
-    def __init__(self, version, session_file=None):
+    def __init__(self, version):
         """Constructor"""
         self.config = ConfigurationFile(findfile("shapeout.cfg"))
         self.version = version
@@ -125,12 +125,6 @@ def __init__(self, version, session_file=None):
         self.spright.SetMinimumPaneSize(100)
         self.sptop.SetMinimumPaneSize(100)
         
-        if session_file is not None:
-            self.OnMenuLoad(session_file=session_file)
-            
-        update.Update(self)
-
-
         # Set window icon
         try:
             self.MainIcon = misc.getMainIcon()
@@ -138,6 +132,27 @@ def __init__(self, version, session_file=None):
         except:
             self.MainIcon = None
 
+
+    def InitRun(self, session_file=None):
+        """Performs the first tasks after the publication starts
+        
+        - start autosaving
+        - check for updates
+        """
+        # Check if we have an autosaved session that we did not delete
+        recover = autosave.check_recover(self)
+        
+        # Load session file if provided
+        if session_file is not None and not recover:
+            self.OnMenuLoad(session_file=session_file)
+            
+        # Search for updates
+        update.Update(self)
+
+        # Start autosaving
+        autosave.autosave_run(self)
+
+
     def InitUI(self):
         """Menus, Toolbar, Statusbar"""
         
@@ -272,6 +287,7 @@ def NewAnalysis(self, data, search_path="./"):
         anal = analysis.Analysis(data, search_path=search_path)
         # Get Plotting and Filtering parameters from previous analysis
         if hasattr(self, "analysis"):
+            # Get Plotting and Filtering parameters from previous analysis
             fpar = self.analysis.GetParameters("Filtering")
             ppar = self.analysis.GetParameters("Plotting")
             newcfg = {"Filtering" : fpar,
@@ -286,6 +302,7 @@ def NewAnalysis(self, data, search_path="./"):
             # - only works if len(colors) matches number of measurements
             colors = self.analysis.GetContourColors()
             anal.SetContourColors(colors)
+            self.analysis._clear()
         self.analysis = anal
         self.PanelTop.NewAnalysis(anal)
         self.PlotArea.Plot(anal)
@@ -454,91 +471,8 @@ def OnMenuLoad(self, e=None, session_file=None):
         
         dirname = os.path.dirname(fname)
         self.config.SetWorkingDirectory(dirname)
-        Arc = zipfile.ZipFile(fname, mode='r')
-        tempdir = tempfile.mkdtemp()
-        Arc.extractall(tempdir)
-        Arc.close()
-        
-        indexfile = os.path.join(tempdir, "index.txt")
-
-        delist = [self, self.PanelTop, self.PlotArea]
-        for item in delist:
-            if hasattr(item, "analysis"):
-                del item.analysis
-
-        # check session integrity
-        messages = analysis.session_check_index(indexfile, search_path=dirname)
-        
-        while len(messages["missing tdms"]):
-            # There are missing tdms files. We need to modify the extracted
-            # index file with a folder.
-            missing = messages["missing tdms"]
-            directories = [] # search directories
-            updict = {}      # new dicts for individual measurements
-            # Ask user for directory
-            miss = os.path.basename(missing[0][1])
-            
-            message = _("ShapeOut could not find the following measurements:")+\
-                      "\n\n".join([""]+[m[1] for m in missing]) +"\n\n"+\
-                      _("Please select a directory that contains these.")
-            
-            dlg = wx.MessageDialog(self,
-                                   caption=_("Missing tdms files for session"),
-                                   message=message,
-                                   style=wx.CANCEL|wx.OK,
-                                   )
-            mod = dlg.ShowModal()
-            dlg.Destroy()
-            if mod != wx.ID_OK:
-                break
-            
-            dlg = wx.DirDialog(self,
-                               message=_(
-                                        "Please select directory containing {}"
-                                        ).format(miss),
-                               )
-            mod = dlg.ShowModal()
-            path = dlg.GetPath()
-            dlg.Destroy()
-            if mod != wx.ID_OK:
-                break
-
-            # Add search directory            
-            directories.insert(0, path)
-            
-            # Try to find all measurements with that directory (also relative)
-            wx.BeginBusyCursor()
-            remlist = []
-            for m in missing:
-                key, tdms, thash = m
-                newfile = tlabwrap.search_hashed_tdms(tdms, thash, directories)
-                if newfile is not None:
-                    newdir = os.path.dirname(newfile)
-                    updict[key] = {"fdir": newdir}
-                    directories.insert(0, os.path.dirname(newdir))
-                    directories.insert(0, os.path.dirname(os.path.dirname(newdir)))
-                    remlist.append(m)
-            for m in remlist:
-                missing.remove(m)
-            wx.EndBusyCursor()
-
-            # Update the extracted index file.
-            analysis.session_update_index(indexfile, updict)
-        
-        self.NewAnalysis(indexfile, search_path=dirname)
-
-        directories = list()
-        for mm in self.analysis.measurements:
-            if os.path.exists(mm.fdir):
-                directories.append(mm.fdir)
-        
-        bolddirs = self.analysis.GetTDMSFilenames()
 
-        self.OnMenuSearchPathAdd(add=False, path=directories,
-                                 marked=bolddirs)
-        
-        # Remove all temporary files
-        shutil.rmtree(tempdir, ignore_errors=True)
+        session.open_session(fname, self)
         
 
     def OnMenuSearchPath(self, e=None):
@@ -599,10 +533,13 @@ def OnMenuQuit(self, e=None):
                 if filename is None:
                     # User did not save session - abort
                     return
-        #self.Close()
-        #self.Destroy()
-        #sys.exit()
-        # Force Exit without cleanup
+            
+        # remove the autosaved file
+        try:
+            if os.path.exists(autosave.autosave_file):
+                os.remove(autosave.autosave_file)
+        except:
+            pass
         os._exit(0)
 
 
@@ -619,20 +556,7 @@ def OnMenuSaveSimple(self, e=None):
                 path += ".zmso"
             dirname = os.path.dirname(path)
             self.config.SetWorkingDirectory(dirname, name="Session")
-            # Begin saving
-            returnWD = os.getcwd()
-            tempdir = tempfile.mkdtemp()
-            os.chdir(tempdir)
-            Arc = zipfile.ZipFile(path, mode='w')
-            ## Dump data into directory
-            self.analysis.DumpData(tempdir, rel_path=os.path.dirname(path))
-            for root, _dirs, files in os.walk(tempdir):
-                for f in files:
-                    fw = os.path.join(root,f)
-                    Arc.write(os.path.relpath(fw,tempdir))
-                    os.remove(fw)
-            Arc.close()
-            os.chdir(returnWD)
+            session.save_session(path, self.analysis)
             return path
         else:
             dirname = dlg.GetDirectory()
diff --git a/shapeout/gui/session.py b/shapeout/gui/session.py
new file mode 100644
index 0000000..5334bcf
--- /dev/null
+++ b/shapeout/gui/session.py
@@ -0,0 +1,140 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+""" ShapeOut - session handling"""
+from __future__ import division, print_function
+
+from dclab.rtdc_dataset import hashfile
+import os
+import shutil
+import tempfile
+import wx
+import zipfile
+
+from .. import analysis
+
+
+def open_session(path, parent):
+    """Open a session file into shapeout
+    
+    This method performs a lot of logic on `parent`, the
+    graphical user interface itself, such as cleanup and
+    post-processing steps before and after data import.
+    """
+    # Cleanup
+    delist = [parent, parent.PanelTop, parent.PlotArea]
+    for item in delist:
+        if hasattr(item, "analysis"):
+            del item.analysis
+    
+    Arc = zipfile.ZipFile(path, mode='r')
+    tempdir = tempfile.mkdtemp()
+    Arc.extractall(tempdir)
+    Arc.close()
+    
+    indexfile = os.path.join(tempdir, "index.txt")
+
+    # check session integrity
+    dirname = os.path.dirname(path)
+    messages = analysis.session_check_index(indexfile, search_path=dirname)
+    
+    while len(messages["missing tdms"]):
+        # There are missing tdms files. We need to modify the extracted
+        # index file with a folder.
+        missing = messages["missing tdms"]
+        directories = [] # search directories
+        updict = {}      # new dicts for individual measurements
+        # Ask user for directory
+        miss = os.path.basename(missing[0][1])
+        
+        message = _("ShapeOut could not find the following measurements:")+\
+                  "\n\n".join([""]+[m[1] for m in missing]) +"\n\n"+\
+                  _("Please select a directory that contains these.")
+        
+        dlg = wx.MessageDialog(parent,
+                               caption=_("Missing tdms files for session"),
+                               message=message,
+                               style=wx.CANCEL|wx.OK,
+                               )
+        mod = dlg.ShowModal()
+        dlg.Destroy()
+        if mod != wx.ID_OK:
+            break
+        
+        dlg = wx.DirDialog(parent,
+                           message=_(
+                                    "Please select directory containing {}"
+                                    ).format(miss),
+                           )
+        mod = dlg.ShowModal()
+        path = dlg.GetPath()
+        dlg.Destroy()
+        if mod != wx.ID_OK:
+            break
+
+        # Add search directory            
+        directories.insert(0, path)
+        
+        # Try to find all measurements with that directory (also relative)
+        wx.BeginBusyCursor()
+        remlist = []
+        for m in missing:
+            key, tdms, thash = m
+            newfile = search_hashed_tdms(tdms, thash, directories)
+            if newfile is not None:
+                newdir = os.path.dirname(newfile)
+                updict[key] = {"fdir": newdir}
+                directories.insert(0, os.path.dirname(newdir))
+                directories.insert(0, os.path.dirname(os.path.dirname(newdir)))
+                remlist.append(m)
+        for m in remlist:
+            missing.remove(m)
+        wx.EndBusyCursor()
+
+        # Update the extracted index file.
+        analysis.session_update_index(indexfile, updict)
+    
+    parent.NewAnalysis(indexfile, search_path=dirname)
+
+    directories = list()
+    for mm in parent.analysis.measurements:
+        if os.path.exists(mm.fdir):
+            directories.append(mm.fdir)
+    
+    bolddirs = parent.analysis.GetTDMSFilenames()
+
+    parent.OnMenuSearchPathAdd(add=False, path=directories,
+                             marked=bolddirs)
+    
+    # Remove all temporary files
+    shutil.rmtree(tempdir, ignore_errors=True)
+
+
+def save_session(path, analysis):
+    # Begin saving
+    returnWD = os.getcwd()
+    tempdir = tempfile.mkdtemp()
+    os.chdir(tempdir)
+    with zipfile.ZipFile(path, mode='w') as arc:
+        ## Dump data into directory
+        analysis.DumpData(tempdir, rel_path=os.path.dirname(path))
+        for root, _dirs, files in os.walk(tempdir):
+            for f in files:
+                fw = os.path.join(root,f)
+                arc.write(os.path.relpath(fw,tempdir))
+                os.remove(fw)
+    os.chdir(returnWD)
+
+
+def search_hashed_tdms(tdms_file, tdms_hash, directories):
+    """ Search `directories` for `tdms_file` with matching `tdms_hash`
+    """
+    tdms_file = os.path.basename(tdms_file)
+    for adir in directories:
+        for root, _ds, fs in os.walk(adir):
+            if tdms_file in fs:
+                this_file = os.path.join(root,tdms_file)
+                this_hash = hashfile(this_file)
+                if this_hash == tdms_hash:
+                    return this_file
+
+
diff --git a/shapeout/gui/update.py b/shapeout/gui/update.py
index b6eab47..6f231d7 100644
--- a/shapeout/gui/update.py
+++ b/shapeout/gui/update.py
@@ -14,6 +14,7 @@
 
 from .. import _version as so_version
 
+
 def check_release(
             ghrepo="user/repo",
             version=None, timeout=20):
@@ -57,6 +58,7 @@ def check_release(
                             msg = a["browser_download_url"]
                     
     return update, msg
+
                 
 def Update(parent):
     """ This is a thread for _Update """
@@ -71,6 +73,7 @@ def Update(parent):
                               wargs=(ghrepo, version),
                               cargs=(parent,))
 
+
 def _UpdateConsumer(delayedresult, parent):
     results = delayedresult.get()
     parent.StatusBar.SetStatusText("Update: "+results[1])
@@ -85,10 +88,9 @@ def get_update(e=None, url=results[1]):
             webbrowser.open(url)
             
         parent.Bind(wx.EVT_MENU, get_update, menudl)
-        # Do not block GUI too long!
-    time.sleep(1)
     parent.StatusBar.SetStatusText("")
 
+
 def _UpdateWorker(*args):
     results = check_release(*args)
     return results
diff --git a/shapeout/tlabwrap.py b/shapeout/tlabwrap.py
index be57fe7..249b30e 100644
--- a/shapeout/tlabwrap.py
+++ b/shapeout/tlabwrap.py
@@ -11,26 +11,11 @@
 import os
 import warnings
 
-from dclab.rtdc_dataset import hashfile
 from dclab import GetTDMSFiles, GetProjectNameFromPath
 from dclab import config as dc_config
-
 from util import findfile
 
 
-def search_hashed_tdms(tdms_file, tdms_hash, directories):
-    """ Search `directories` for `tdms_file` with matching `tdms_hash`
-    """
-    tdms_file = os.path.basename(tdms_file)
-    for adir in directories:
-        for root, _ds, fs in os.walk(adir):
-            if tdms_file in fs:
-                this_file = os.path.join(root,tdms_file)
-                this_hash = hashfile(this_file)
-                if this_hash == tdms_hash:
-                    return this_file
-
-
 def crop_linear_data(data, xmin, xmax, ymin, ymax):
     """ Crop plotting data.