I've noticed this on my netbook too. However it comes back after a minute. It's done this for years.
I am new to this so...I don't know what else to say but
The OS I am using is: Windows Vista Home Premium SP 1
It seems to happen alot when I change my volume with the nob on my netbook
What's going on?
Could malware be involved? I have Trend Micro Internet Security and Webroot spy sweeper and nothing has been detected