I7 920 temperature control issues

I have an i7 920 on an ASUS P6T with 6GB of Corsair DDR3 1600MHz RAM and Windows 7 Ultimate 64 bit. My issue is my system is overheating under heavy load, such as Re-encoding a DVD to an MP4. When idle, the CPU is at 25c, but when I am trying to encode, within 3 minutes, the CPU is at 95c and the system bluescreens. I am using CoreTemp to verify these temps. I am using an admittedly cheap cooler, but it is a 4 Heatpipe design, which has to perform better than the stock cooler. The system is NOT overclocked or has the voltage been tampered with. I thought maybe I had too much heatsink compound on the heatspreader, so i cleaned it off with alcohol and spread a very thin layer across the spreader, reseated the cooler spinning it a bit to get out any air bubbles, but it still overheats. I'm wondering why the thermal protection doesnt kick in and slow the cpu down, instead of crashing. I am considering going watercooling and is why i went with such a cheap cooler, so I could save for a decent watercooling kit. I know this is out of the ordinary, and I am wondering if possibly either there is something wrong with the motherboard configuration for the CPU or the cooler is inadequate. Any input?