Sounds like deto to me also, but have you checked the plugs around those parts before you put them in.. Ive seen a box of autolite spark plugs do the same thing....
O no no no im just trying to get people to get them while there "hot" you know with all these orders they aren't gonna last long.....too bad billy mays turned his nose white otherwise he would have contacted me to sell these things.....
I have also heard of wrapping in a plastic bag(a couple of them) putting them it on a 2x4 or something and filling the cooler with expansion foam but make sure you close the lid....quickly!