It does my head in every time I use Poser and want to undo something.  Say I rotate an arm, move the camera to view from another angle, and then decide I don't like the movement I made to the arm.

What happens when I hit undo is that it will undo the camera movement first, then the second click it will undo the arm movement.  It's a pain in the arse because I don't want it to undo the camera movement, that's just for observation purposes, I just want to undo the last arm movement and keep the camera where I put it.