Checked the info on the Windows Update version and it says "January 2007". What the hell? This is why I never (normally) use Microsoft updates for ANY drivers, but this one time I had faith in Windows 7's obviously great line-up of built-in drivers so I figured what the heck.
Anyway, Updated my driver from the Gigabyte mobo website and all is good now ... so far! Driver date 7/30/2009 and version 7.5.730.2009 ... now lets see how TF2 works.