It sounds like the cooler has a not so perfect cooling surface, as in one of the heat pipes is sitting proud from the rest. It may also be that the retention system is warped, but I would assume the problem lies on the cooler and not the mount. You cant compensate for something like that. If it were the mount, then a washer (or shim) in the right spot would have shown some sort of result. So you can either return it and get another (the odds on another bad one are pretty slim), or you can lapp it. If you go the lapping route, then make sure to lapp the CPU as well. The CPU should be lapped to at least the same grit as the cooler. If you decide to lapp it then let us know and I'll be more than happy to give some instructions on how to lapp an exposed heatpipe cooler like the 212. But given the bother with lapping, I would recommened an exchange instead. Lapping isnt hard, but you'll spend $10 to $25 for the parts to do it unless you already have them and thats money you could have spent on a better cooler to begin with. Whatever you do, dont try to reseat the pipe if you can find out which one is causing the problem. They are soldered in to the aluminum retainer and it will simply crush or bend instead of seat further into the retainer.