iDVD only recognizes built in superdrives. your gonna have to export your dvds as isos and burn them with disk utility or toast
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Macbook Pro 15.4" 2.53GHZ Core 2 Duo 4GB RAM
Powermac G5 Dual-Core 2.3GHZ 2GB Ram
Powermac G4 Quicksilver 733MHZ 1.25GB Ram
iPod Video (1st Generation) 60GB