I gave up on my X-Fi Titanium and Vista Combo last week(Didnt see this thread until today). But if you are experiencing Random crashes with the above combo you might want to try these drivers.
http://forums.creative.com/creativel...cending&page=1
A Little History on Daniel_K.
Creative has made crappy drivers forever. With Vista, the problem has gotten worse. Daniel_K took it upon himself to fix Creatives Drivers. (In the past, He made some questionable mods to the drivers too, but thats another story). He now has the blessings of Creative to release his drivers to the public.
With my X-Fi in place, I would Crash Every day.. Usualy multiple Times. Once I pulled it out and went back to my Onboard audio, my crashes stopped. This is a clear indication of driver issues. These drivers should help quite a bit if you are experiencing crashes with your X-Fi/Vista system.
Completely Uninstall every creative driver from your machine before installing Daniel_K's drivers!
Best of luck folks, Let me know how it goes.