I have had an ATI 5670 for quite some time, and has always worked fine, until I bought a GTX460 and tried running it in my system, due to only 1 PCIE connector, I was unabled to power the card and therefore the system wouldn't recognize it.
I switched back to my HD 5670 and now when I turn on my pc and start a game, the screen turns black, the last sound played is repeated over and over again till eventually I am forced to restart the PC via the power button. The PC recognizes the card and shows the latest drivers installed
Pheom II X4 965 BE 3.40Ghz
8GB GeIL Black Dragon RAM
ATI HD 5670
Corsair 430W PSU
I've tried install the new drivers and changed the thing in BIOS to run through the PCI first, and tried changing it to the onboard GFX, which works perfectly fine.