Yeah, we've run into that and in the Southwest sun, sometimes these boxes will run very hot. I had considered that, but at 3:00am this morning, the box is hanging wide open with an ambient temperature of 50F and it still had the problem. I can't imagine that temp played an issue under those conditions.
That was with both, the radio that's been in service on the tower for about 7 months and a brand spaking new one.