q9550 CPU Hot (100c under load)

I know there have been a lot of "CPU hot" posts recently, but here's another one: ~60c while idle, ~100c under load

ASUS P5QL-Pro
Q9550 not OC'd
XIGMATEK HDT-D1264
Antec 900 Case
Arctic Silver 5 thermal compound
CORSAIR CMPSU-750TX 750W

I've used Core Temp, Real Temp, PC Probe, and ASUS AI suite, and they all report roughly the same temp. I haven't been having -any- problems whatsoever with the computer, games run perfectly at this supposed 100C temp, but this still worries me quite a bit.

I replaced my hsf, cleaned the thermal paste off with 91% isopropyl alcohol, reapplied a small amount and put it back in, making sure all the pins clicked (even though the MB felt like it would break, you have to push them so hard) - same temps.

I replaced it with the stock hsf, cleaned/reapplied paste, same temps.. Took the fan off again, cleaned/reapplied paste, and made sure for the 1000th time there was no connection problem between the heat sink and the cpu, no change. My 3 120mm fans (and the 200mm) are set on high, the cables are tucked and neatly routed, so the airflow should be pretty good. Nothing else is running hot, my MB temp is around 30C, the case feels rather nice.

Using Real Temp to test sensors, I get 13, 12, 14, 14 for my 4 cores, but I still wonder if it's somehow getting the wrong temp.

If it was the motherboard/psu, wouldn't I be having some other problems? Does anyone have any ideas about what I could try? At what point would the cpu just shut down from too much heat?