Does System Profiler recognize the burner? What does it say? Unfortunately prior to 10.4.4 (Tiger) Apple always wanted you to buy their internal Superdrive burner, and generally would refuse to recognise the burning capabilities of an external burner, at least as far as built-in software was concerned. There is a utility called Patchburn that usually at least allows Finder and iTunes to work with an external burner; you might give that a try. Also 3rd party burning software such as Toast will generally work without the patch, but Toast is not a free program.