Odd graphic glitches on 7600GT, *strictly* only after resetting

Hi everybody, I would like to ask for suggestions on a strange video issue. Starting with the specs: I'm running a nearly new (3-week old) PC, which has a C2D E6600 fitted on an ECS 650i SLIT-A, plus a single hi-performance DDR2 2GB stick. Video is provided by a 7600GT video card plugged on an LG 1753T monitor via an analog cable, all powered by a 450W ThermalTake.

My problem is that, after rebooting the computer with either a soft or hard reset, graphical corruption takes place from BIOS screen. Glitchy black streaks run vertically through the screen, while font of memory testing data and such looks yellow where said black lines cross them. Under Windows XP SP2 (early February nVidia Forceware, 169.21 IIRC) I get to the XP logo screen still with the lines and then it gets stuck on a BSOD (error code 7E, the first of the other hex addresses is 00000005 and there is no mention of a driver). Switching to Fedora Core 8 (recent drivers from livna), it goes through the Kernel loading stage with the lines and then the screen goes black by the time the GUI should be loaded, although there are signs that the system is not crashed, for pressing power after waiting about one minute leads to a clean shutdown (console messages still visible). The only pre-existent issue I can think of was me overwriting nVidia driver installations. That caused some additional configuration mess-ups, but since them I removed all drivers and did proper fresh installs.

The strange part is I have no other problems elsewhere, such as graphic corruption under games or random crashes after long usage periods. The glitches will go away by turning off the power instead of hitting reset and then turning on again a few seconds later, or else by resetting multiple times. Overheating does not seem to be a problem, as GPU temp stays at the 50ºC - 55ºC all over and the glitches happen after a reset regardless of how long I had been using the PC. Now, do you see another possible cause for this other than a faulty GPU in brewing? Any suggestions for other areas I could be looking upon?

Thanks in advance!