I just ran into this problem last night and yes...the northbridge heat sink interferes with the arctic cooling freezer 7 pro. I think I am still going to try and get it on there tho. I can get the heatsink on with the fan detached and the northbridge heatsink will push the bottom fin up a tiny little bit. The problem is the fan shroud surrounds all the fins and cant be bent like the fins can. So what I am going to try and do is cut a small section of plastic out of the fan shroud to give clearance.
Now ive just gotta find something to cut a small piece out of the plastic
I know this is a pretty old topic....but heres ur answer