Hmm.. yeah creative sound stuff is pretty sketchy when it comes to their drivers and things. Did you take a look at their alchemy project they are working on?
The stuff I read on it seems like its actually microsofts fault on this one when it comes to vista as they have changed the way sound works I guess by removing the HAL so you cant get EAX and stuff in games, but thats where the alchemy comes in by using openAL.
"Creative ALchemy Project allows you to run your favorite DirectSound3D games on Windows Vista as the developers intended - with full hardware accelerated 3D Audio and EAX support! This is done by translating the legacy DirectSound calls into OpenAL. In order for this to happen, a couple of files need to be installed into each game directory. This is handled automatically by the ALchemy installer - but can also be performed manually by advanced users."
Taken from their page at Connect creative labs.com