It's an unfortunate fact of life that many softcos follow Microsloth's lead and produce upgrades that tack on more new features but don't address outstanding issues in the basic program. This is because Marketing like to be able to put out stuff saying "Now has feature Y!!" rather than "Feature X now works properly!!". Never mind multiple undos, it's ridiculous in Poser 4 that moving the camera prevents the last undo to the figure, and that you can't undo an accidental deletion. If P5 has not fixed these quite basic issues, it's very sad.