Honestly, it doesn't sound as if they heatsink is seated properly. Granted, I'm using an Alpha 8942T but my load temps never exceed 48-49c and I'm talking Prime load there. I've noticed Prime load is usually 1-2 degrees celcius hotter than a normal SETI load. My system specs are in the .sig.
Btw, did you say say yet which mobo you are using?