Sound/screen sync?

[IIIBarcodeIII]

Hello,

Today i've updated windows to SP1 - thought i'd give it a second chance from this problem last time, clearly its not been resolved or theres something wrong with my system what only happens when I update XP Home to SP1.

What happens is, if I get something like a MsgBox notification, I get the dialog at the normal 'speed', however a small part of the sound is played... a small pause... then the sound begins to play again (in this case, the Windows exclamation sound).

Another example would be the navigation sound (the click), i've disabled this anyway seen as I hate it but it goes c....lick (only way I can describe it on a forum ^^).

All my drivers etc are upto date, any ideas whats causing this?

Barcode
(I know I could just disable the sounds, but I like them to be there if you see what I mean )