God, I am such a hater, but I have to do this. Creative just released new drivers for the X-Fi that addresses some issues with Vista, but lo-and-behold...Creative gives us crap again! I cannot get my X-Fi to work properly in Vista either. The sound is all jacked up. I have a dual-boot, damn thing runs great in XP, terrible in Vista.
C) See if you can get your money back and get a better sound card like the ASUS Xonar or the HT Omega. Wish I could go this route.
I think C is the best option. Asus Xonar D2X or Xonar DX and HT OMEGA are indeed serious good sound cards.
Some company just can't learn their lessons.