I use an external DVD burner on Firewire because my iMac's Superdrive is broken. How do I direct iDVD to burn to the external drive, since it wants to default to the broken Superdrive? I can direct iTunes to burn to the external drive just fine, but I haven't figured out how to manipulate iDVD to do it. No answers contained in iDVD Help. Any assistance? thanks--Pete