CPU dies at 55C; time to change CPU, cooler or both?

Hello all, As mentioned in the thread about my glorious cooling problems: I seem to be in a posession of a CPU that dies when it reaches 53-55C. Is it time to buy myself a new CPU, should I just get a better cooler, or should I change both while I'm at it? Any suggestions on a brand/type for the cooler? Regards, Pieter