Incorrect tracking with Xperia Z

[micahscopes]

This is awesome, thanks for sharing! However, on the Sony Xperia Z, there seems to be a limit for turning my head to the left. When I get to about 90 degrees left, suddenly the whole view turns clockwise 90 degrees and starts rotating up about the Y axis (say the Y axis is the one normal to my face at initialization).

Sorry for the confusing description, but the point is that I'm not getting complete 360 degree motion!