I have Ubuntu Gnome 13.10 x86 on my old ~2007 iMac. It is not dual booting and it runs an intel processor. It has 2 GB of RAM.
My issue is that after I push the "Shutdown" button from the user menu the system just stops in the middle of the shutdown process. To be specific at the "Will now halt"
Plymouth works (the boot screen still moves) and i can press ESC to view the consol output. I also noticed that modem manager was not shutting down properly so I uninstalled it because I use Ethernet at my place.
Another error message is: Mount '/' busy I think that is the main consern but I can't figure it out. I have o hold the power button down.