ok... i've just tried a new 112D with stock firmware... the 1.09
and i have the same problem. I can't burn DL disk burn im able to burn single layer.
BUT!! i can burn DL with CloneDVD! wierd!
so now that i know thats a problem from ImgBurn and not the burner, i will ask on the right forum
but if someone know something, please let me know here!