Mac Keyboard Hotkeys issue

I have an iMac with OSX (10.5.8) (dual core one). I have Vista Business installed with Bootcamp and everything is working well. When I first installed Vista, I was able to use the quick function keys (ie. F1/F2 controls brightness, F11/F12 controls volume) but now after a year it stopped working. I only get the standard function keys.

In windows bootcamp control panel, I navigated to the Keyboard tab and there's only one option to "Use the F1-F12 keys to control software features". It was deselected. No matter what I do (select and apply or deselect and apply) the quick keys won't work. Heck I've even tried it with pressing down the "fn" key. Nothing gets those keys working. I've even tried reinstalling the keyboard software located on the CD that came with the iMac.

Anyone have any suggestions on how I can get those keys working again?

Edit: The keyboard came with the iMac. It's the ultra-thin aluminum keyboard. Also the IR remote isn't working too. I used to be able to control volume using that as well. The remote option in the Bootcamp control panel is NOT set to disable.

 

I actually think the problem was caused by Windows Update. Yes right now it's on the latest update. The keyboard used to work, now it doesn't.

 

Any have a solution? It's still not working...