http://brainbit.wordpress.com/2010/0...ified-drivers/
Someone took it upon themselves to release better drivers for Xonar cards, as well as some others.
I had an issue with my DX where the drivers had auto volume normalization that couldn't be turned off. It however didn't work nearly as well as the normalization built into MPC-HC. These drivers took care of that issue.
If anyone has ever used kx, Daniel K, or YouPax drivers, this is a similar concept.