This happened to me. I cannot burn discs with WL 9.0.35 64 bit but I can burn with WL 9.0.35 32 bit. Never have figured out why. So I just use WL 32 bit for all my burning. I have updated the drivers and run the checking program and no errors found. One of my interns is a computer wiz and he finally through up his arms in disgust trying to figure out why. It was suggested by members of this forum that I reinstall windows (Windows 7 Pro) and maybe sometime in the future when I have nothing else going on and I can afford a week to do that and reinstall all my programs I will. Until then I just burn with WL 9.0.35 32 bit.