I have a set of files in .mds and .mdf form that came as multi-.rars. When I go to burn the image, Alchol 120% tells me that the .mds is an unrecognized format, even though it is clearly in the list of accepted formats. If I manually choose the .mdf file to burn, I must manually enter in the Mode, Form, Block size, Header and Trailer, etc., when the 'playstation' setting usually takes care of all that. If I then manually enter in the correct Mode, Form, and Block size, leaving the Header and Trailers empty, I burn a coaster. Why won't it recognize the .mds? Any help will be greatly appreciated.