Issues with Audigy soundcard and antivirus not getting along under XP Pro

[muzician21]

Running into audio issues that are 1) Selective and 2) apparently some
kind of conflict between antivirus and an Audigy Platinum EX
soundcard.

With the Audigy selected the audio gets borked under some apps -
Windows Media Player, Cakewalk Home Studio2 (multitrack audio
recording app) and Pinnacle Studio 9 (video app) but no problems under
Soundforge (another audio app) and Media Player Classic.

This occurs after installation of Microsoft Security Essentials or
Bitdefender. Remove the antivrus and the problem goes away. However,
it doesn't happen with an M-Audio Audiophile 2496 soundcard.

I've used the Audigy without issue along with Bitdefender on other XP
machines. This is the first Core2 Due machine I've had. Could that be
a factor?

Thanks