For some odd reason my OS X 10.6.3 retail disc is not booting up when I startup my iMac (Mid 2010). However the DVD can be read just fine by the computer when the OS is running. More importantly, if I try to use that same disc on another iMac (Mid 2010) to boot up, it works without issues. If I try a System Restore disc (which didn't even come with my computer (OS X 10.6.4) the computer boots up the DVD just fine So I'm just wondering, what gives? What can I do for my computer to recognize my OS X retail disc when booting up? It does show up when I hold OPTION key. But after that there's no action in the DVD drive when selected.