Install Menu Meters (easily found on versiontracker.com) and watch your CPU utilization. Apps go crazy occasionally (Safari does this more than occasionally.) and take 100% of the available CPU cycles. This will heat up the processor and make the fan turn on. Use 'top' from the command line to see which process is hogging the CPU and quit and relaunch it. Fan will turn off in about 30 seconds.<br><br> -- Dan<br>