Have you tested stability with something like Prime95? I had my CeleronD at 3.6, but fournd that it generated errors in Prime95... Had to back it down to 3.4 GHz.
I used the CeleronD 310 so to run it at 3.4 I can get FSB up over 200... Not bad performance for a $65 chip!
No I did not not test with Prime95, just tested with games - did not crash and BIOS has been set to "HALT" on all errors.
I've backed it down to 3GHz anyway as I don't want to push the CPU to far as it must be near it's limit.
Good value $$$ chip alright.
The next PC I build though will use a AMD Athlon 64 3500+ 939 as they are better for gaming - faster, cooler and slightly cheaper than genuine prescott P4's. But I'am going "against the grain" as I have never had a INTEL CPU fail, and I don't know how reliable AMD CPU's are in normal operation/OC and there length of operating hours before replacement is required.