Apple pro keyboard no Volume or Eject Key

Hi,

I'm running OS X 10.5.8 on a EMac, with the original Apple Pro Keyboard.

The OS X install is a Fresh Install, as when I got the Computer it was passworded locked.

No matter what I do, the Eject button and the Volume buttons above the numeric keypad on my "Apple Pro Keyboard" do not work.

The volume buttons seem to work a little in iTunes, if I press and hold the button for a very long time.

I have tried the Keyboard on my MacBook Pro, and it works fine.

I have also tried a Kensington Slim Mac keyboard on the Emac, and after going through the un-recognised keyboard wizard, that worked fine as well (including the Media Eject and Volume keys).

I tried to do a PRAM reset on the Emac, but that doesn't seem to be a facility of this computer.

The EMac is an eBay special, and only cost me $10 ;-) but it seems to be functioning fine apart from this issue.

Please help me solve this problem, as it's driving me crazy.