problems with maze-4 chipset on a 865p board

i got a bunch of watercooling stuff (see sig) and it all works great but whenever i use teh maze4 chipset block my computer wont boot. i have no idea why, the thing is seated properly and i have reseated it several times allready.

now if i put my stock asus NB sink back on with some fresh ceramique it works fine, any ideas?

could it be because the mounting system is applying too much pressure on the clips?

Maybe it's detecting no RPMs from fan header of NB fan and refuse to boot? Have you checked that route? Try plugging a fan in with the chipset block mounted.

His mobo is an Asus P4P800 Dlx. It uses a stock passive NB sink. No fan...