Ummm, I'm guessing this may be a silly thing to mention, but have you checked the speaker setup in control panel?
Sounds and audio devices;
Volume (tab) - Speaker Settings section at the bottom;
Advanced button.

This allows you to define the speaker combo that's actually connected.

IIRC, there is also a related access to controlling what speaker combo is connected in the Creative software (don't have a Creative card in this PC so I can't check to confirm) but I believe there is a specific Speaker Settings applet available in the start menu for just this purpose.

I do know that if this/these settings aren't correct you will only get stereo.


--=-- My credo: If it's worth doing, it's worth overdoing - just ask my missus, she'll tell ya laugh --=--
You're only paranoid if you're wrong!