I just installed an EVGA 9800GT and its giving me some snap, crackle, pop on the sound. Its not an extreme case, but its definitely there, and its definitely because of the card. Its also annoying.
When I tested the problem on a fresh install of Win 7 64-Bit, the video card driver wasn't listed in Windows upgrade like it was with my old card, so I went and downloaded it from the NVidia website cause I wanted to get the latest one. Right after the install, the pop and crackling began.
I'm not all that sure what it is yet. If anyone has any ideas that might fix it I'm all ears.