Same here, perhaps it just has to do with the fact that they are all 8800 series? That or maybe it's brand, I know I use EVGA and I'm pretty sure BaldEagl does to.
I know that EVGA had a card BIOS update in mid 2007 for the 8800GT that altered its fan speed settings. As I recall, the new BIOS is set with a fan speed of 30% to start, and then it will throttle up to 100% to keep the video card's temp in the mid 70's.
Different vendors are free to set their BIOSes the way they see fit.
-Llama
-Llama