There is a problem with G5 and G4, if you connect the keyboard at the front of the Mac OR if you connect the keyboard to the monitor. If you do so, you will nor be able to open the CD/DVD tray - SOME times........
Lars Damgaard
If you do not want to save any of your stuff, you can format your harddrive and reinstall systemsoftware - no problem.
Lars Damgaard, MacSupport, Denmark.
This problem is a font problem or a harddisk problem.
Try to disable all fonts and restart the Mac.
Otherwise - take a copy of your harddisk (Carbon Copy), reinstall the system (NEW user) and copy your programs and User Data back.
Lars Damgaard, MacSupport, Denmark.