Well, with the slim amount of information that you have supplied here, I consulted my crystal ball and came up with the following opinion:
The problem, as far as I can tell, is that your slimline drive doesn't like your choice of media since it doesn't even know that the disc is in the drive, if you put the disc in the drive to start with.
(Hint) We generally would like a description of what you've tried to do for yourself. Maybe know if you bothered to read the FAQS and Guides section and maybe tried to use the search function...just a thought.