Just grasping at straws here but - have the Rampage Extreme and using Thermaltake liquid cooler which has an H shaped backplate. The RE has a capacitor on the underside of the booard that fits smack in the middle of the H.
Essentially, I ignored it and put the H plate on it and was able to get sufficient tightening for the cooler block to make good contact.
There is no metal to metal contact as I have an insulator between the cap and the plate but is there any way that this setup could cause problems with a stable clock?
Thanx