Undo/Redo in GUI

Using the Mac GUI, R version 2.0.1 (as well as 2.0.0), the undo command 
undoes way too much.  I have had times where I was editing code, made a 
typo, unconsciously hit undo, and saw the entire document disappear.  
Other times it goes back to what looks like the state when I opened the 
file during the current session.  Thankfully the redo command works, 
but this scares me every time it happens, my peace of mind would be 
helped by making the undo command a bit less aggressive.

My apologies if this is a known issue.

Thanks,

Ben Lauderdale
Economic History
Ludvig Maximilians Universit?t
Munich, Germany