FWIW, I'm there with you. I really like some of the new features in Poser 5 (the nested subfolders and the cloth room), but the memory leaks and unpredictable crashes are just driving me to distraction. The only workaround I've found to help at all is the one Eric uses; shut Poser down every hour or two and then reopen the application to free up memory and re-stabilize things.

Of course, doing that still doesn't help with things like the freezes caused by the P4 lightset bug, or the intermittent render bug (same thing you described, where Poser just greys out and hangs indefinitely after a render), or the Wacom tablet bug, or the off-standard cr2 format that screws up the Tailor, or an awful lot of other very, very irritating problems. I've got a real love-hate thing going with Poser 5 right now.