Windows 7: sound distortion

When I bring my Windows 7 HP desktop out of sleep or hibernation, all the normal system sounds play in a distorted manner. If I reboot, then the sounds play normally. I have an on board 5.1 HD 6 channel audio codec and have removed the driver, then got Win 7 to find the latest driver (Microsoft) but that makes no difference.
On my purchase order details I find:
Microsoft UAA Function Driver for High Definition Audio Adi 1986, not sure if that helps though! If I try to play anything in my media folder all I get is a distorted hiss, I can't detect any 'music' at all.
I don't really know what else the try right now!
any pointers would be great.
Thanks.

I got round this by getting a USB sound card, by passing the onboard audio. Looks like the Microsoft driver doesn't work.