I have an internalDVD/Cd rewritable drive unit model DRU 510A. It was made in nov 2003. It is a 4 x max burner. I has worked fine for years until this week when I recorded DVD from files on my hardrive. It does not seem to get past the checks. I use Nero 6.6xxx and used the tool information. The sony seems to like DVD + R only to write to. I have used many different type of blank DVD without difficultly. So I replaced the DVD with a new HP DVD 940I and it wrote to the same blank DVD that gave me an error message. The Sony looks dirty and I wonder if that was or is the problem. It would be nice to fix the old DVD as a backup on an old machine or Linux machine. Any ideas?