Just caught on to this thread. Alright, so I have a very similar setup. I use pieces of the silver insulating blankets used on water heaters between the cages and a lower 'stat setting and don't have any issues. What is your 'stat set at?? If they are all being double heated in the same way (top and bottom) then adjusting your t'stat should balance it back out. Also, are your rhp's on the stat and your lights on a regular strip?? And lastly, what are you keeping in these and what are your cage and ambient room temps?

~Kat