So far my samsung xbox drive has only failed to read 2 types of media both being dvd+r (memorex and sony)
I have found 6 dvd+r brands that DO work, and every dvd-r and dvd+rw I have tried work.
So far no cdr has failed to read That i have tried.
Its by far the best drive, Ive modded 16 xbox's now, with various drives, none of the (retail xbox type) drives come near the samsung.