Pressing CTRL-Z or selecting undo from the menu when the undo queue is empty (e.g. when you have not done anything yet) causes Java to spit out a method call trace on stdout. There do not seem be any ill effects, though.
Confirmed. Should be easy to fix.
Redo has the same problem.
Mads, this should be an easy thing to fix. Do you want to give it a try?
A fix has been checked into CVS