I've seen a lot of people with this error. You have windows 7, right?
Try disabling any and all hibernation settings in the control panel-->power settings.
In the device manager, what is listed under the audio devices?
Download memtest, and let it run overnight.
Look up your motherboard, and see if there is an updated BIOS.http://support.asus.com/download/download.aspx?SLanguage=en-us