Are you able to use a Audigy 2 ZS Platinum with this x64 Vista Ultimate SP2 driver and still do Dolby Digital 5.1 Direct Recording? Or can this only be done on under Windows XP? Also, does it matter if you have 4GB or 8GB memory installed? What features are lost if more then 2GB of memory? Interested in sound playback and direct dolby digital 5.1 (maybe DTS-ex too) recording really.