Well I personally have my 2.6ghz CPU overclocked to 3.225ghz and it has been running Stable as a Rock like this for about 4 years and my CPU on a Load on a Hot day rarely breaks 40c But I am a special Case as My cpu is one of the Best Overclocking CPU models You can get (800Mhz FSB Northwood core) so I wouldn"t expect to get these Type of results with an AMD or Prescot or newer P-4 Core and I also Run a Huge Cooler (Zalman CNPS7000-CU Moded with a 50CFM Fan) and many Case Fans and I have a Motherboard that supports advanced overclocking Features Like setting the FSB/DDR/PCI/AGP all seperately without affecting each other.....
I knew before Hand that i would be overclocking so I chose all of my Components very carefully so I could get this Type of Performance out of a Much slower CPU......
Cheers