I had this problem with an 8800GT and then decided to go ahead and buy a new GTS 250. Same problem still persists. I tried using older drivers after using Driver Sweeper and that did not help. I tried the beta drivers and no luck there either. I tried increasing the TDR delay to 8 seconds, no luck. I disabled TDR, but then it just hung the system. I'm fooling with memory now, hopefully that works. Specs:
BFG 250GTS 1GB (Brand new)
Windows 7 Pro 64-bit
Asus Striker II Mobo
250 series is 9800 with a new sticker and a bios update. 9800 is an 8800 made with a smaller (55nm instead of 65nm) process. Only real difference in your old card and new card is a small jump (128 vs 112) stream processors and a bit more ram. They're basically the same card, sorry
I have had this happen only twice, and both times it was when I was loading into the game at the character selection screen. The first time was quite a while ago, right after STO launched. The second time was this morning. A reboot resolved the problem both times. I am running a GTX 295 with the 196.21 drivers.
I honestly don't play anything else besides STO on the machine right now; so I can't comment on other games.
Just thought I would add my name to the list of concerned users.