Well shite. I didn't even have to start up UT for the problem to surface tonight. It happened right after boot up. I moved the cursor towards the icons on the left side of the screen, and the plaid patterns started. I moved the cursor back to the right, and then to the left over the icons again a few times, and it seemed to make the problem worse. So I did a quick reboot and now all is well. -For the time being at least.-
It's odd that you mention heat. I was wondering that myself, but this Dell has had a noisy fan for over six months. After following instructions that were emailed to me to no avail; I finally got pissed off enough to call Dell India ( *&%#@ why can't I talk to someone in Texas any more?) and we went through a process of elimination.
i.e. Did the same shite all over again. (*&^%$#!)
It's not the CPU fan. It's not the fan on the vid card. That leaves the fan in the power supply. But the dipshite in India wasn't satisfied and wanted me to disconnect the cd and dvd drives from their power connectors, and disconnect the ribbon cables. The only reason I could get all the other connectors undone up to this point while he waited on the other end of the phone was due to the fact that I had already sweated and cursed them off previously. I finally gave up and told the fokker that the arthritis in my hands was preventing me from going any farther. (Not entirely a lie. :p ) Supposedly whatever is wrong is still covered because I reported it before the warranty ran out, but I'm still pissed off that Dell feels I should do most of the warranty repair work myself.
The moral of this diatribe is:
Don't buy a fokking Dell! They ain't like they used to be. That company SUCKS BIG TIME now, so avoid their product like the plague!
OK, rant over.
To get back on track:
-The fan on the vid card is almost certainly still good. But if it isn't, can it be replaced?
-The inards of the computer are clean. I cleaned when I put in a second hard drive, and I cleaned it again before I did all the trouble shooting BS on Dell's behalf.
-Heat build up seems unlikely, because the computer had just finished booting up when the problem surfaced this time. And the CPU fan is still noisy, so at least it's still working.