[jhautz]

Do you have one of the newer ones with the switching BEC in it? If you do, the external BEC shouldnt matter.

Check to see that the heatsink scews are tight. I read somewhere in another forum that somebody was having issues with this and their heatsink screws were loose and it effected the cooling.

Also check that you didnt blow a capacitior. That could cause it tor run hot as well.