I took my AC Freezer 7 off the other day to de-dust it as it had been running a little hotter than usual and I broke one of the clips as I put it back on. I personally think the clip-in setup isn't the best design but I really cant be bothered removing my motherboard to fit a back-plate one.
They go in just fine first time but if you ever have to remove it and re-seat it the clips are prone to wandering and catching on the mobo as you try and fit it.
It now idles at 60 degrees and hits 80 playing CSS
might look at one of these as a replacement.