AMD 2100+, 1GByte 333 DDRAM, GeForce Ti4200, 1HD (80 GByte) +1HD (160GByte). Win XP Pro. Still running with SR3 (German Version). Didn't have any problems until yet. Poser uses a lot of CPU power. I had big problems with Poser4 in the beginning on my new PC, because of overheat (CPU cooler only worked sporadically). No other application caused me troubles at that time. So have a look at your mainboard and CPU temperature as a pre-caution.