Smartpack problem

I have 2 ETC Smatpacks configured to 12 1 K dimmers and hooked up to single phase. I had been having problems with 1 of the packs where the center group of dimmers 5-8 would flicker randomly and then shut down. When I look at the temp reading in the diagnostics it the middle temp reading is much higher than the other 2. I am now havint the same problem with the second pack. Any idea on what the problem could be?