Okay, so I have come across this very annoying problem. I have Mac OS X, Leopard - in an iMac and Flash CS3 on it. It was all good, until about two weeks ago, I just couldn’t undo. I mean I can’t undo. Command+z, edit->undo, nope. Neither work and I can’t undo what I just did. Draw a line, press cmd+z, nothing happens. Yeah. I tried fully removing CS3. All components, programs, shared components, preferences, everything. Reinstalling it again… still the same ■■■■ deal.
I hope someone can enlighten me on this.
Edit: Stupid me. I had a custom keyboard layout and it, without me knowing had y and z keys swapped. So nevermind, lock, trash, delete this…