What program are you using the burn them? If you're using iDVD, it needs to be a built in SuperDrive unless you have the latest version of iDVD and then it only supports certain DVD burners.
The Disc burning built into Finder I think requires an Apple built-in SuperDrive (DVD Burner).
If you use Toast 7, nearly any burner should work.
This site should fix your issue:
http://www.macfixitforums.com/php/s...Forum39&Number=645408&page=&view=&sb=&o=&vc=1