My audio is skipping, and cracking really bad.

In my case uninstaling ATK0110 ACPI utility driver solved the case. This is probably power management problem as someone already noticed. This ACPI is an interface enabling the system to control voltage, temperature and so on.
This is probably a solution for Asus mainboard users only.

BTW things that didn't work:
- high performance power profile
- updating drivers to the newest (I heard cracks in both soundcards - Audigy (with kx v.3550) and AD SoundMax integrated with MB)

My ultimate solution to this was, unfortunately, having to reinstall Windows 7, which did fix the problem and from that day hence, I've had no audio problems with either card that I used. I can only guess that something in the OS glitched and reinstalling was the only alternative.