Sounds Like a bug.
And if your haveing problems with your sound card try to a system restore
Click your start menu .
Go To Programs.
Than Accessories.
Than System Tool's
And Click on System restore.


And Try to scan for any Virus on your PC.

Here is AVG From Download.com Work Good.
Search results for AVG Anti-Virus Free Edition 7.5.467 - Free Software Downloads and Software Reviews - Download.com


Chris B......