Symptom: The drive works fine with CDs and CD-Rs, but it won’t work with DVDs or DVD-Rs or DVD+Rs etc.
The drive works fine with DVDs, etc, but it won’t work with CDs.
Answer: The drive has two different lasers, one for each generation of media. One of the lasers is no longer working. If the drive is still under warrenty, get it replaced. Otherwise just buy a new one.