K8N - Wont shut down windows,hangs with hard disk LED on.

I just upgraded my system and got a K8N motherboard and athlon 64 3000+.
I have a seagate sata 200gb hard disk and an audigy soundcard in there
too and not much else.

Everytime I try and shut down or try and restart windows my computer
will show a little hard disk activity and then *i think* at the point it
would normally shut down or restart it just hangs with the hard disk LED
on constant. I am forced to either hold the power button in or hit the
restart button.

I know its not a great problem but It would be nice to have my new
system working 100%!

Can anyone suggest a fix for this problem? I cant see any way to turn
the onboard sound off in the BIOS, can it be done (might fix my problem)?

Many regards

Dan B