I had the same exact problem with my 9860. While playing ANY 3D game for a bit this problem would start happening. It's cyclical, I got the sound glitch and then poor fps, then about 1 min later, sound glitch and smooth fps again, then it would reoccur about 5-10 minutes later. Also had the same phenomenon where the fans would ratchet down in speed like everything is being way less taxed and so it doesn't need the same amount of cooling, as a poster above said, "sorta like it was taking a rest." I performed most if not all of the troubleshooting mentioned above and even completely reinstalled Windows XP. After the reinstall it seemed to be OK for a few days then right back to having the same issue. Finally after about a month of this I started having the boot problems which pointed to a MOBO failure. The machine eventually died all together and now I have a big silver 15 pound paperweight. I'm now about to send the entire machine back to Sager for a MOBO replacement. Hopefully all will be well after that. So, word to the wise, if you're having this problem and you're still under warranty, SEND IT IN! This all happened to me 1 month after my warranty expired. I'm betting it IS related to the "known issue" of MOBO failure in these machines.