Pretty much my line of thought (except I factored in PPC/architecture when I should've just said pre-Leopard/OS), and you were more technical and detailed at it. I'm happy that Apple finally got rid of those device profile problems and stuck to standards (finally).
It worked, but the Toshiba DVD-ROM (can't remember which model) wouldn't let me play Region 3 DVDs (when it was set correctly) and just spat out the discs, the Samsung SD-R5732V wouldn't let me burn past 1x. I returned them and got Pioneers the next day. Obviously, there were no problems then (under Panther).
Anyway, DSL67 doesn't seem to be checking back... He must've just plugged an external in and found out it works instantly.