sw 2007 sp1.1 shaded views lagging

I just updated from 2006 sp4.1 to sw2007 1.1. My display area is lagging quite a bit whenever i pan or rotate the view. The lag is worse the closer in i am zoomed. Also the lag clears up when i switched to a non-shaded display. This lag was not an issue for me in 2006.
Is there some way to optimize/tweak the shaders?

My system:
Win XP
4GB RAM
ATI FireGL v5000 (8.163.1.0 drivers as certified by SW)

Regards,
Nick