It may well be the case that as Salmon T is suggesting. However before rushing out to replace the drive there are a couple of things i suggest.
1. Download the free version of "CD burner Xp"
http://cdburnerxp.se/download.php and give it a try and report back to us.
2. Try and find an opportunity to remove the optical drive and place it in another computer (actually you need not physically install it in a bay).You can just connect it to the power and ide cables (setting the pins as needed) and see if your results are different on the other computer.
There can be various causes for the issue you are experiencing including the one ST has stated. Let us know the results of these suggestions before replacing it.truenorth
