This is most likely a heat issue. My M6811 recently started exhibiting the same behavior. The problem is the two vents on the rear of the machine. They become clogged with dust very easily. Blowing them out from the outside, is only a temporary fix as all the dust trapped in the vents will get blown inside and eventually make it's way back to where it was and cause the machine to overheat again. You need to get inside and blow the dust out, not in. Don't try this if your machine is still under warranty. There are plenty of guides posted on the net about opening an M6811, so I won't go into the details here. You just have to get in there with an air compressor or a can of compressed air and blow on the inside of those vents until they shine and no longer have hairy, powdery build up on them anymore. I keep my machine on my lap, so I noticed a huge drop in the case temperature, and my fans hardly ever go anymore since I unblocked the vents. I also picked up about 25 minutes of additional battery life because the fans aren't struggling all the time to keep the thing cool. Just a warning, though. If you plan on blowing the vents from the outside using your breath, be prepared for an eyeful of dust from each one. It may take 3-4 really good blows to clear them enough to bring the temperature down. When I first checked mine, I felt NO airflow coming from the smaller vent at all. After blowing, a warm draft was definitely noticeable. Hope this helps.