Bug: Undo (CTRL-Z) crashes EDP

[Alexo]

EDP crashes when undoing changes using CTRL-Z

Here's how I reproduce it:
1) Start EDP with "empty files"
2) Type some characters in the right pane, and hit <ENTER>
3) Hit <CTRL>+<Z> (undo)
4) EDP crashes. If it doesn't, repeat steps 2-3 until it does.

[psguru]

Thanks. The fix is coming in the next build.