Suddenly my DVD burner doesn't work (using Toast & Popcorn , 24" iMac), and gives me various "Medium Sense" errors. This has happened in the past with previous versions of OS X (currently on 10.5.7), and was always fixed by repairing permissions. Now, however, that doesn't fix the problem. Additionally, when I run "Repair Permissions" a second time, and a third time, fourth time, etc.....It keeps finding the exact same differing permissions, as if they were never fixed the previous times. Of course, when it's done running, it tells me they were all fixed. Then I run it again, and it finds all the same differing ones again. Does anyone know how to repair "Repair Permissions"??