Finally got around to doing this (had to go to michigan to help restore power). Anyhow, disabled onboard gpu, rebooted, reinstalled nvidia latest drivers, rebooted. launched wmc, mb3, selected a movie, mpc-hc fired up, hissing popping and gurggling began. wth?
swapped pci-e slots, same thing.
placed a temp ground from the slot plane screw to the other ground, same thing.
Swapped power connection from PSU to VDO card, no change.
disabled card, rebooted, enabled onboard gpu, rebooted, fired up into windows, loaded latest 4600 drivers, launched into mpc-hc, no feedback noise. sob.
And i'm about 35 days from time of purchase at microcenter now... darn.