I read your other thread and personally think you ought to RMA it, but if you don't I guess this happens alot with ABIT boards and those new NB clips. Alot of people are making paperclip hooks (U's actually and putting them through the hole the clip vacated) to hold on their heatsinks and they are working fine. You might go check over at the ABIT forums to see if there is anything special about doing that.
I wouldn't mount the northbridge with thermal epoxy.