I transferred my BP to a new cage today and I noticed some worrying discoloration on its underside. Here are a few pics:

http://i.imgur.com/2DuNO.jpg
http://i.imgur.com/GsTIA.jpg
http://i.imgur.com/lMB7f.jpg
http://i.imgur.com/KGyVO.jpg

I switched her to coconut fiber from some recycled paper mulch or something which was approved by a pretty knowledgeable local herp store owner, and I think that it may be wedged in between the scales and causing the dark marks.

So, what makes me think it might be a burn is that when I lifted up her hide on the side of her tank which has a UTH she had moved away most of the coconut fiber, so she was just laying on top of glass on top of UTH. It's a Zoo-Med 10 gallon UTH w/o a thermostat. Now I have her on a thicker layer of substrate in her new tank, and I'm working with a thermostat to decrease the temperature of the UTH.

So, what is it? How can I help her?