I have experienced loss of the side right speaker sound every time I run New Vegas. This does not happen with any other games I play, and this problem began some weeks ago, not sure just when. I can resore the sound either using a restore point, or un/install of my Audigy 2ZS card drivers. Any suggestions to fix this recurring problem is appreciated.

Windows7 Pro x64
Audigy 2ZS
I7 2600k
ASUS P8P67 Deluxe
eVGA GTX460