Too Many fans per header is my first guess & if you plan on running more than 1 fan per header on the main unit your going to need to cool the AQ5 Fan Header VRM's, Either by putting a smallish extra fan connected from your M/B to blow cool air to the rear of the AQ5, but I suspect with the amount of fans your wanting to run your going to need the Waterblock to cool the VRM's enough (if your using a Watercooled PC?)... The slower you have your fans running the hotter the fan VRM's will get....
Or you need to get some POWERADJUST 2's to split those fans up abit, you can quite happily run at least 2 fans per PA2 fan header (you can add up too a total of six extra PA2's) & this is probably your best bet

N.