iOs 5 first gen iPad.

iOs 6 third gen iPad.

Both will on occasion lose the right margin such that it cuts off the last half of a letter on a line.

It seems unpredictable though I alternate between Mantis and Note Taker HD when I study.

Might Note Taker HD may be leaving something behind in a register?

Typically a power off of the tablet will fix the issue but recently had the third gen iPad refuse to fix the problem with a power off. I had to delete and reinstall Mantis to fix the problem.

Have never seen the problem on the iPhone 4s

I've noticed that happening too since the last update. When my right margin was set a "20.0" it wasn't as noticeable. But when I changed it back to the default of "10.0" it really is. I can't figure out the cause. To reset it I double press the home button , find the mantis icon, hold it till the red and white circle with a dash in it appears and select that. Then relaunch the program.

I also have since discovered the remove it from memory fix.
Playing with it I have also determined that Note Taker is not responsible. It does it occasionally even when Note Taker is not in memory.