the reason being is mac use a different format to windows and this also extends to their native cds/dvds macHFS is the format. So windows will only see the iso9660 part of the image file as the disk you are going to burn are dual format. The parts that windows sees are only the small files in the iso9660 section of the disk that used for booting it. So unless you install a filesystem that can read MacHFS you wont see them but as the previous poster pointed out if you just burn the image to disk this should give you the right disk.

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