I had a screen come up that told me there was a serious problem with my DVD burner.

I called the mfg (LaCie), who basically told me that if that screen came up, it was all over. As a last chance long shot, before trashing the burner, he said, try one using one of those cleaner discs that people use to clean DVD players. I did, and it actually worked again.

These things do malfunction, even (or perhaps especially) if they are not used much. There are a couple ways to deal with it--

First:check the mfg website for FAQs, fixes, and maybe even a user forum.

Second: Google something like "LaCie DVD Burner won't recognize disk" and read til you find a suggestion that you like and understand (remembering that a lot of "tips" only make sense to the person who wrote them)

Third: Resign yourself to the fact that these things turn to junk more often than they should, and buy a new one--