I have a 15" 1.33GHz PB with 10.4.2 installed. My F1 -F5 keys no longer work. Nor does the restart button. My expose keys, F9 -F12 do, however. It's not the keyboard, because I find that I cannot restart from the Apple menu, either. This has happened before, but I don't recall what fixed it. I have run fsck, permissions fix, etc, but no love. The only way to restart the machine is from the command line. Anyone else experience this??