What I've noticed, a bit in the same order of idea, is that when you try to delete a frame of the animation, from the Animation Frames Dialog, whether you do it by pressing the "Del" key, or right-click "Delete".
Then, C2 has stopped working, crash, back to windows.
Also, I'v just tried the "Duplicate" ramones mentioned and twice in a row did C2 crash.
Nickydude: I'm not sure what you're talking about there.
As far as it goes for me, whenever I click on the animation dialog, it gives it the focus, and I can work in it as expected. Once I'm done and clicking on the image editor dialog giving it the focus back, of course then the animation dialog goes beyond in the bacgkround.