Right recently after I installed my Vista 64 bit on my PC i had some Driver problems with my Sound Blaster Fx Fatality sound card, everything worked fine a part of my microphone so i spent good few hours trying to sort it out installing uninstalling drivers adding greative consule,smart recording and blablabla.... nothing really helped.
The solution was quite simple! Here is how and what you should do if you have a similar problem. There are two solutions either you can roll back a sound card driver to the previous version which apparently worked just fine and the latest ones ain't working properly on Vista 64. If that still doesn't work make sure you are using High Definition Audio Device and plug the microphone in integrated sound card on your motherboard instead of the one on your Fx-Fatality cards!
If you are on Vista first time and you are having some problems or dunno where and what to enable this link might be useful!
http://www.demondigital.com/tutorials/vista_recording_sources.html
With your Fatality sound card it should look a bit different something like this
So once again make sure you are using HD Audio Device from your motherboard while there isn't a new driver or a fix for latest version! Hope it will help!