When all else fails. Try this.
Do a clean install of your card. By that I mean go to Add/Remove Progams and get rid of all that Creative stuff.
Then go to Start/Find/Files or Folders... and do a search for Creative and dump that.
Power down and pull your card.
Power up without the card in so that Windows "sees that there is no card in".
Reinstall your card.
Let Windows find it.
Then using your original installation CD, select Custom and just put in SurroundMixer/AudioHQ/drivers. Uncheck everything else.
Then go to Creatives site and download any updates by date issued.
Then install updates in the order issued and reboot after each install.
I've used that procedure for every Creative card I've had