disable audio enhancement in your "sound properties"
i cant believe how much cpu usage saved is done by unticking this option
yes i have the x-fi xtreme music too
only issues i had is with riva tuner which doesnt show up video memory usage anymore
else my tv tuner and games, curerom, daemon tools, yasu etc all works well
check to disable tcp offload some people say on the net
that is when you cant connect to some website but can still ping ip adress.
for me it was another options, disabling "interrupt moderation" on my nforce 4 nic.
though my problem is a bit different, i could connnect to google.com but not...