Well, that explains it. It looks like you should be fine, but I don't think that putting that CPU at full load with that cooler is the best idea for longevity. I could be underestimating its thermal tolerance, but I like to be careful. You might want to get say a cheap $20-30 cooler just to be safe. Heck, a decent cooler would also mean plenty of overclocking headroom if you want to give that a try.