I'd sort out your lights, if the heats stopping you from getting the lights closer you should change them for cooler lights. It sounds similar to a problem i had when i started growing, my lights were too far away and the seedling stretched to get closer to the light and the leaves started pointing upwards and looked like they were closing. It may just be a weird one off problem as emmpey suggests but you need to get your lights closer anyway, around 2".
I'd back up what emmpey says about planting before the root gets to an inch also, i find that if i let the root get long it bends and that causes problems, plant when the root first starts to pop out of the seed.

Good luck :rasta: