Hi movieGraphix!

If there are troubles with your video drivers, try to switch from openGL  to spree in Poser and see if that helps.
If problem is still there i dont think its a driver issue.

In Poser 7 its also good do reduce the numbers of undos in your preferences (5 is good).

Personally I think P7 is very slow and unstable, scenes that crashes P7 for me renders perfectly in P6.

Regards / Jonny