There must be something very wrong then. With a Xonar there should be absolute silence, it's the first thing you notice coming from onboard sound, how quiet the silence is. Could it be the speakers?
There was silence when i used the card for the first few months but it just happened from one day to the next.
( im not trying to hijack this thread but i hope we can figure this out together)
I will try and look at my irq settings later and see what i find.