...I didn't quite get your description of your fan setup. If the fans in and fans out are not equal, and don't produce a well distributed flow through all compnents from in to out you are just blowing air around in there. Turbulence and vacuum negate the whole effort. It can even be that all fans are spinning, but very little air is getting moved where it counts.
Zalman's claims are based on an ideal flow in and out of the case, including all the heat dissapated by the Zalman HSF. If you don't have ideal case air flow in and out, it doesn't make much difference what you plunk on your CPU.
It's tricky and often illogical, ask any aerodynamics engineer.
Right now, on my P4 3.06 giga, running SiS Sandra Burn in, I have:
Room temp 24C
CPU idle 29C full load 37C with short blips to 40C
NB idle 37C full load 42C
GPU idle 41C full load 47C
Case idle 26C full load 31C
I'm not happy with the GPU and Northbridge numbers, and I know it's because the air flow just ain't right yet. I'm using both software to read internally and probes to external LCDs and watching both. The differences aren't constant, but at least I know the box is operating in a healthy range.