In my own experence, the super drive can read mini CD (I personally did that before). At the end, it's still just a CD, size doesn't really matter. However, the Mac Pro super drive is quite picky on the disc, even some normal full size disc can be unreadable in the Super drive (low quality disc?). In this case, plug in an external optical drive (the normal PC one, not the Apple USB super drive) is the easiest way to make the cMP can read the disc.