Radon X1950 Pro 256MB GDDR3
On Windows Vista Ultimate x64.
It does it after running 3D games/apps usually.
Seems to go away after not running 3D for a bit.
Oddly enough, when I run DOOM 3, no artifacts show up in game whatsoever, but in EQII they are all over the place. I thought maybe heat? But, this did happen when I still had XP with temps topping at 51C underload, but only did it in EQ2 after some tweaking. Never on the XP UI obviously since it doesn't run 3D.