This started after a patch a few weeks ago, though may be in no way connected:
Mostly it happens when my spell book is open especially when memming a spell. Weird graphic glitches dance across my screen such as black webby triangles, 1/3 of the screen flashes green, etc. It is very psychadelic.
Did a complete file scan a few times. Had a friend over who tried messing with UI files (deleted one and repatched it).
Is there some obvious simple thing we missed doing?