I just can't believe that so much heat was absorbed by that back panel that it fried those leaves like that. And as far as it being so reflective that it burned them I don't believe that either. Fluoros just arren't that hot to make surrounding areas so hot and especially as far away as you have them. I've got leaves laying right on the mylar with 43 watt fluoros right next to it and they don't even begin to burn. And from what HD suggested in a different thread, burning from a reflective surface is not something you have to worry much about from CFL's. HID's yes.

Also I see that almost all the leaf tips are burnt. From what I understand that suggests that you're maxed out and a little over the max ferts the plant can handle. So you might want to back off ferts a little.