As a start, the following details will help: Poser version (including full version number) Operating System. System RAM. I've found that sometimes quite trivial-seeming changes to a scene can hit RAM limits on my system. A consistent change of behaviour could be a sign of a virus or trojan, lurking and using a bit of RM. I know that there were utilities which could clean out the Windows Registry, which can gradually grow. A utility which displays memory use can be informative, and frightening. OK, I'm guessing, but hitting the physical RAM limit can really mess with how Poser runs. My experience, it's the first thing to look to.