@Bandolin: Windows XP and 2,5 GB RAM works okay. Windows 7 need 2 GB of RAM for stand alone because it is full of flashy kitschy graphic nonsense. So use any other 3D software program and you have the same problems you have with Poser now. Or you switch off all Windows 7 related graphic stuff.

But what is the idea of using 3D software and less than 6 GB RAM AND NO 64bit anyway? Get realistic. You'll never have a smooth workflow with your RAM of 2,5 GB RAM except you go back to Win XP.