Mold on seedling's starter boxes?

So I bought a jiffy propagator with space for 50 seedlings and they went about nicely, i routinely sprayed and added water and kept perlite at the bottom. They were staying in a footlocker at the end of my bed with 2 cfls and 2 computer fans running.I opened it up today to find the small rectangular boxes that they come with, I'm not exactly sure what they're called, but they were covered in some sort of white mold. I think one actually harmed one of my short rider seedlings. Any thoughts as to how this may have happened?

too much humidity you say you routinely spray it..how many times a day?? cool moist places are the perfect environment for mold to grow

Probably too much, it was pretty freakin wet, I think i was thinking the more the better.... I dumped all the perlite and ditched the top to see if them just thriving with circulating air at this point wold be good, they're already pretty big. i just want to make sure its not some ridiculously poisonous mold.