Bug? OS X See Windows 7, XP or Windows 8 Release Preview Installer Burned on Rewritable as Blank

Hi. A Windows 7 (even the Windows 8 Release Preview) or XP Installer burned as backup on a rewritable can't be recognized by Mountain Lion anymore. It sees it as a blank mounted as an Untitled DVD but when you test the rewritable on a virtual and a real PC, the DVD works. The DVD media is 4x DVD+RW (not DVD-RW). What could be a workaround?

Gbu.