Trying to combine 2 ISO files, project burns OK, but DVD player says "DISC ERROR." i notice that adding ISO file #1 will include the smaller "MDS" file, and adding the #2 ISO file will not, repeat, will not add its smaller file...Does this smaller file (in ISO image#1) somehow control the overall size, or some other factor, thus causing the disc to fail? Project verifies fine but just won't play. What to do? Couldn't find what i needed in Cynthia's instructions, but this may be my fault...many thanks!