I have the same HSF combo, excpet mine is the all copper one. I've got other cooling as well but I think I just got lucky and got a good OCable chip. I've left it burn-in at 249FSB for several days....all was well. As soon as I bumped to 250.....then Windows will sometimes reboot, games will crash randomly, sometimes it wouldn't POST, things like that. I can see the RAM is being taxed (it has the LEDs) and it's always interesting to see what happens just right before my machines craps out.....the LEDs are peaked, maxed to the brimm.
I will have to forfeit the idea of 250FSB and stick with 249.....damn....