How do you get the Volume keys to work on a G4 w/ Leopard?

[krye]

I helped a friend install Leopard on his G4 PowerBook. That machine has dedicated keys for volume up and down (F4, F5). Now with Leopard, those keys don't work. We tried going into System Preferences > Keyboard Shortcuts and tried to add Volume keys for iTunes. We added F9 and F10.
They do show up in iTunes > Controls as an option, but don't work. They trigger Expose. So we disabled Expose and still, F9 and F10 don't do anything.

So how do you get the volume up and down keys to work on an old PowerBook? I guess that same goes for the brightness keys too.

 

[TodVader]

I have no problems on my iBook G4 with 10.5. Every F key works like in 10.4.

 

[operator207]

In default mode, the F keys are not F keys until you hold the FN (function) key down.

Try holding the FN key down (bottom left) and hit the F keys you assigned. See if that gets them to work.