The pushpin socket 775 mount is a poor design in my books.  I was having problems, traced it to the cpu cooler mount.  Found one of the pushpins only had 1/2 of its plastic there to secure properly. Slipped out of my fingers, fell on the hard wood floor onto the retracted pushpin mounts, they all broke.  DAM.  Where am I going to find this old mount?   Hmmm.   Look at ToolKit, grab 4 #10 course thread 3/4" screws, through the cpu cooler turn into pushpin holes in motherboard.  Hey that feels pretty solid.   Fire it up, been working flawlessly for weeks.  Going to replace this machine before T2 , but kept it in the game till I can upgrade.