GPU-Z interfering with power?

[CanaryInTheMine]

so, i've noticed something really weird...  maybe it's known already and has been discussed, but I haven't seen a topic on this.

anyway,

if I leave GPU-Z running on sensors, after a while, one of the cards begins to throttle GPU utilization.
I noticed this on a system with 3 5850s first.

Then, I was messing around on a system with 2 6990s and added a dual GPU 6870.

well, the powercolor 6870 x2 has awesome sensors, one of which is the Amp draw.  and what do you know, while GPU-Z is running, after a while, the power draw fluctuates like crazy.

solution?  exit GPU-Z and whoila, everything runs at 99-100% GPU utilization.  weird, weir, weird....

any explanation?