The key map on my Acer Aspire 5750 keyboard has gone awry since I had the keyboard replaced (because of physical fault with one of the keys).

The new keyboard looks identical, but now Ubuntu seems a little confused about which (function) buttons are which.

So previously Fn+left/right were, as marked on the keys, brightness up and down; Fn+up/down were volume. It all worked as advertised! But now Page Dn (which is marked as Page Dn or Back a track with Fn) is turning the volume up, and the others fn+arrow keys don't work at all.

Is there a way I can see what's happening or get it to re-map my keys?

Thanks.