possible that the contact between the HSF and cpu is not strong enough, check that cpu itself is seated right (there are no bent pins on the grid array). did you apply the right amount of thermal compound/paste?
monitor temps through BIOS with default settings. 98 C is just 5 C less than the threshold
You idle at 44c? I think thats my load temp. A cool to the touch heatsink doesn't mean all is well because if its not touching the CPU right, it will stay cool because its not picking up the heat. It should be warm. Only other software I can think to try is PCProbe?
Dont worry too much about your max temps unless load temps are consistently more than 75 C. Stock thermal compound would be good enough though you may have done a fresh application since your reseated the HSF. Your temps (idle and max) depend a lot on the ambient/ room temp as well. your temps are fine at 57-58 C load