Ok... 6x is the slowest my burner will go... got two different makes/models actually, an asus external DL and a Sony DL internal. Both do it, no matter what speed I burn.. I did have the first one I burned at lower speed work what seemed perfectly, so I went to the next backup, and the imperfections are there still. Guess I will try some different media... Or maybe switch to DL disks, even though they hurt the pocket book quite a bit