Aha...that explains what is causing my screen freezes in SWTOR. That game engine just cannot handle that much diversity. So many of us in my guild are experiencing this problem and BW cannot or will not address the problem.
Actually, it is very possible it is conflicting with their game engine somehow. Today I did another clean install and did NOT install PhysX. Made sure I set all the nVidia graphic settings in the control panel to "performance" over graphics as usual, and restarted the game.
What a difference. Screen freezes were not evident even though I went into a raid for a hard mode. Nice and smooth. No problems at all now.
...sigh...certainly would be nice if there was a standard that could be followed easily to make sure game experiences are clean.