This is bugging me. I have a Volcano 7+ on an XP2000+ overclocked to 1725 MHz. When I first installed the HSF, idle temps were about 39-40 C and full load about 44-45 C. After about 2 weeks, the idle temp starts to climb to 45-46 C idle and 48-49 C full load! So, I took off the HSF, cleaned the bottom, applied a little bit of Arctic Silver 3, and re-installed it. Perfect: temps back to where they should be. Now, it has been about 2 weeks and the temps are climbing again! Before anyone says anything, let me say I am putting the correct amount of TIM on the CPU: Just enough so the core is fully covered. There is only a tiny bit of "oversquish" of TIM on the sides of the core. Therefore, the issue isn't about too much or too little TIM. The HSF uses the 3-hole clamping style so contact pressure can't be the problem. The temperature in this room is fairly constant too. I keep the fan speed to medium cause the noise on high is too much. I am not using a shim either. One thing I do notice when I remove the HSF to clean it: The bottom is "dirty" with a sort of film (oxidation?) I have to use alcohol and scrub to remove it. Is there an issue with the Arctic Silver contacting the copper? I am thinking of trying the plain white stuff the HSF came with as a test. Anyone else have this type of problem or suggest a way to fix it? The part that bugs me is the fact it takes about 2-3 weeks for this to happen.