Someone else had this happen a few weeks ago and I've experienced it as well. I didn't see any obvious corruption in the file though I didn't go through it line by line. I think maybe this is just one of the occasional "mystery" problems that no one has figured out yet. Sometimes Poser just seems to develop an aversion to a particular pz3 and won't have anything to do with it. Post partum depression?

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken