Overheating?

The Pi is currently running as a simple ftp server and web server for a webcam setup, so it's running standalone, and very stable.  However when I'd tried xbmc etc, this seemed to drive the system very hard, and the screen would blank out and processing appear to stop.  The CPU appeared too hot to touch, so I put this down to overheating.  Well, some enterprising soul on ebay is now offering copper heatsinks which fit the cpu and are low profile.  I've ordered a couple and it does seem to bring down the temp.  I've not had it hang in a quick test since fitting the heatsink!  Your mileage may vary.