When i woke up today, i tried to start my computer. nothing would happen...i start my Imac again but this time holding the alt key and I see my mac partition is gone. Put the mac os install cd in... looks at disk utility and sees my mac partition is now unmounted and named untitled... kinda looks like evwerything disapeared overnight. i have the exact same problem as this guy: http://forums.macrumors.com/showthread.php?t=287652 My mac partition has the same data information as this guys im linking. Im running on mac os x 10.5.2...or i was and have an intel imac 2.4 Anyways im kinda new to mac and need advice...i got too much thing that i dont wanna loose on my hard disk. If someone could please help me. no one has any ideas???