I just returned to the Poser world a couple days ago from a ~5 month hiatus. After installing SR3 I encountered problems similar to those mentioned above. Mainly, after opening a scene and rotating the camera a bit, Poser would stop responding and I'd have to kill it. After going through a few hoops in an attempt to fix the problem, I recalled I'd had a similar problem with Poser 7... I checked my rendo forum post history and found my old solution here.

Seems to have fixed my problems so far. Hope this help!.