I have a Radeon HD 6850. After playing a game two days ago, the fan speed stayed constantly above 4000 RPM (shown by HWMonitor) even after restarting and with low CPU performance. When starting the PC the speed is immediately high. Temperature is 37 °C (shown by CCC and HWMonitor). CCC says the current speed is 22 % (no high performance applications are running). Enabling manual fan control in CCC and changing the value has no effect on fan speed. Drivers are said to be up to date. What is the problem?