I'm running 10.5.6 on a 24" iMac. I tried to install Ubuntu on an external drive (new at this). It seemed to work, except after the install, it said I had to reboot so I did but instead of booting into Ubuntu (or OS X for that matter), I just got a folder with a question mark (where normally the grey apple is when booting into OS X). I then disconnected the external drive and restarted, thinking I could boot into OS X on my internal drive but once again I got the folder/question mark icon. So right now I'm running off my OS X backup firewire drive. Strange thing is, when I am booted into the backup drive, I can see my iMac's internal drive on the desktop and when I look inside, everything seems to be there. Did Ubuntu screw up a system file?? I've tried selecting the internal drive in "System Preferences>Startup Disk", and it allows me to select it as the startup disk, but when I restart it won't boot to the internal drive. I either get the folder/question mark, or if my backup drive is connected then it reverts to booting to that one. Is there any way to fix this besides copying my backup drive over to the internal drive? I'd prefer to avoid that, since it will take a while and also my backup is a week old. Anyone who can help will be saving my iLife!!!