I have an audigy 2 zs as well as onboard sound, the audigy ran all the main sounds while the onboard sound ran my comms, everything ran fine until 3 weeks ago when the troubles started, no particular event started it, no recent driver or hardware installs. Ran diagnostics on the RAM and harddrive, no problems. After a while the crashes happened usually when on comms, I tried uninstalling the audigy and reverting to just the onboard sound, still got the crashes then vice versa, ditto the crashes, then tried doing some tests, playing a song on windows media and running the game at the same time, still the same crashes, by this time I was convinced the problem was sound related. As usual every driver had been uninstalled and new ones loaded, virus checks ran ad nauseum.
The answer as usual was found somewhere between what I had learned and Googling, I disabled the onboard sound via CMOS and used the audigy only and so, after running the same tests that crashed my system everything seems to be ok.
Now that things seem stable other questions come to mind...
1/ was it something I did?
2/ microsoft updates?
3/ driver malfunction?
4/ my motherboard telling me something?
5/ Franks bunny-hopping upsetting my system (see BF2)

Vin with fingers crossed