Impossible to rectify some errors in delta editor within open delta

[GoogleCodeExporter]

What steps will reproduce the problem?
1. I accidentally entered '2.00000000000000' as a real number character
2. Click on the next character

What is the expected output? What do you see instead?
I expected to be able to click on the accidental real number character and edit 
it to its correct value but clicking on I was unable to open the character. 
viewing it in the grid view also produced an error on screen (the character 
concerned was not viewable). In the end I had to open up the CSIRO versin of 
the delta editor and correct the mistake there.

What version of the product are you using? On what operating system?
DELTA editor 1.0 5/21/2013
Run on Windows 7 Professional 64-bit

Please provide any additional information below.

Original issue reported on code.google.com by [email protected] on 12 Jun 2013 at 2:39