Sounds strange i have to admit - but check this out for a laff to cheer you up - i put the following into google to see what else has shown up related to this problem,
control panel audio speaker audigy zs blank problem
Clicked on a link about 5 down - not really reading the title just teh bit that says Soundblaster Audigy 2 ZS Platinum Pro problems, and THIS thread pops up on Cableforum...
Doh! Bit too specific on the google there.
