Ya man, i know how frustrating watercooling can be, trust me. I hate having to un-loop and re-loop over and over when all of a sudden you get a weird problem. HATE IT! That's the big problem with watercooling...

Anyway, thanks for pointing out where you got the back-plates and core protector. I had completely forgot about Sidewinder Computers.

As for your problem, i would bet it's a bad mounting... Maybe adding a 120mm just in front of your 3 cards but i doubt it would make much of a difference for the moment. If you hit 100c running 3DMark06, imagine what you'd get running Crysis maxed out...Heh

2 questions comes to my mind tho, are you sure the pump(s) you are using for your GPU loop are correctly working (Flow going on normally) ?

And what radiator are you using for that GPU loop ?

EDIT: I can't seem to find the Microcool Core Protectors on SWC.com... I'm probably just blind... Can you shoot me the link?