Another question occurs to me: what tool did you use to cut the rigid insulation down to size? Hacksaw with a fine blade, or something else entirely?
I used an utility knife. I don't know if it is the same insulation that you are using but I used RMax insulation. I got it at home depot. If you don't use the plastic sheet to cover the insulation I was told to have the shiny side in to reflect back into the chamber.