Im actually running the Intel BX2 motherboard, and the same happened with the evga i have. So its not chipset related
Its happened with the last few releases of Nvidia drivers,
I dont think its a Creative issue as i tried on board sound aswell to test but im not ruling it out.
Tried Re-installing Vista
Changing options in 2142 to med , changing sound options, non worked.
UAC is off and running everything as administrator.
Think its wait for a patch or driver to fix, although it would help to work out which bit off software is at fault