I did a 9V fan mod with Nidec fans using a LM7809 voltage regulator. I also have the fan divider mod. My JTAG 360 (Zephyr) has rebooted a few times while playing NHL10 and Forza 3. I have a feeling the fan on the side of the GPU is bad as it doesn't seem to be moving nearly as much air as the CPU side. Stupid question, but have to ask, should both fans be blowing equally?