Just got a new keyboard, the Microsoft comfort curve 2000, and everything seems to work fine except for the 'back' and 'forward' multimedia keys.

I am running Ubuntu 11.10 and have tried going into system settings -> keyboard -> shortcuts, then I try and hold down the keys to set the action I want them to perform, but nothing changes.

Any thoughts on where else to look?

-- UPDATE --

I rebooted and the options to change the keyboard shortcuts seem to be working now. Now I can tweak the whole thing and I managed to assign the media keys correctly.

Thanks to everybody for the suggetions