Did you burn the disc using this drive previously or was it made on another machine?
It is possible that the data is corrupt, though this is becomming less and less common. Check the disc and if possible try it in another machine to see whether or not the disc can be read. If it is unreadable on another machine, then it is possible the data has been burnt incorrectly, though if it does work, then your drive doesn't currently support the format. This may be remedied by updating the drives firmware.
Is there a particular error, or does it simply not know that a disc is present?