Intel's mounting mechanisms leave some to be desired. I had a problem with my LGA 1066 Xeon where the heatsink got disturbed a bit and I got a Dimm slot error. Turns out you can inadvertantly put the socket pins out of place if the CPU is pushed down too much in one area. Luckily just pulling the CPU and heatsink off and replacing them was enough to fix it.
Aside from that the official Intel docs only specify the need for the land grid to withstand 30 processor insert/remove cycles which is kinda lame but I guess in most cases you'd never do that many.