There is a 3.1 update for PP12/Poser 9. Not sure if that's your problem, but you're missing an update or two ;). Every scene, when opened, caches texture files, so (it's been my experience anyway) that the longer you have Poser open, the more you change things (like textures), the more different scenes you open, the slower it gets. I just save and close and reopen every so often ;).

Laurie