I've been getting consistent "Unhandled Exception" errors, and/or crashes to desktop, and/or freezing (during loading screen) since the last patch.

Last night playing DG, I got a freeze about 20 minutes into a multiplayer match, & upon rebooting:  no video at all.  No CMOS/BIOS error beeps.  It sounded like I was booting normally & fine, but I was unable to 'blindly' login to Windows.  I tried multiple hard boots, tried swapping my vid card (GeForce 9800) from one PCIe slot to the other, tried different monitors, etc.  No video, but the card had power.

I had an old PSU (550W, 4 or 5 yrs old) & was planning on buying a new one anyways, as well as a new vid card (although further in the future) so I bought both.  Swapped in the new PSU & got the same symptoms.  Swapped in the new vid card (GTX 260) & video was restored.

With the old card, I never had adverse symptoms other than occasionally crashes in already known unstable games, & frequent crashes in DG.  I never had any overheating symptoms (corrupt graphics, etc).  Only thing I can think of is my PSU wasn't able to keep up, but would that really fry my vid card like this? 

I've never had a card just die in or act like this in the past 15 yrs.  Does this sound like the PSU coulda fried my card?  Has anyone else ever experienced anything like this?