I have Vue6 and poser 7 on a mac (intel). Vue disappears from time to time- but only a time or two was it completely unable to recover the scene (and that was frustrating, not because I lost work- but because it tried over and over...wasting about an hour before I gave up and said "no thanks" upon restart!)

I don't use many rooms in P7 other than the pose and material room (and occassionally the cloth and hair). I don't think Poser has ever just poofed, though.

I went through a phase of trying to make posable trees and just created my cr2 by hand before loading it up to tweak the joints, so I guess I was doing the phi builder thing. I never had any trouble....but, of course....I would end up with only a half dozen body parts most of the time.