The problem is that it is Realtek. I had the exact same problem recently with the card that came with a new computer and you can find hundreds of references to the same problem on the net. I have used quite a few sound cards over the years, from the dirt-cheap to the professional. I suspected the Realtec would go out pretty quickly, but the computer was so cheap it didn't really matter. Besides, Realtec has been around long enough that I figured they may have made some improvements by now. Not so. Just buy another card. You would be better off with a generic no-name Chinese card than with a Realtec.