[doviatt]

The fdisk -l just lists current known partition info. Non destructive. Try this and post results. I have access to some Mac Mini's I can poke at to help trouble shoot and try destructive things to so you don't have to loose your info.

Edit: fdisk -l /dev/sdx/ (use sda or sdb etc if sata or hda hdb etc if ide)
Edit 2: ok the above doesn't work on mac. I'm still checking how they define their drives.....