Ubuntu and the FN key: how to get it to do what it is supposed to?

[Bre]

Using Ubuntu: Does anyone know a way to get the the number pad work when pressing the FN key? Is there a keyboard configuration file available anywhere that can be loaded specific to the T500 that will make the FN key do the things it is suppose to do in general?

Perhaps a file for xmodmap or xkb? I'm not clear on the syntax of those programs so I am reluctant to start tinkering with them myself. Is there a configuration file available somewhere?

[Bre]

I'm sorry, I forgot to mention that I'm on a T500

[ColonelONeill]

What should the Fn key be doing that it isn't? Do you mean the special function keys like Fn+F6 and Fn+F8?

[tshiker]

The Fn + NumLk keys enable the number keys for me in Linux.

Thinkpad t400 Ubuntu 12.4 -WinXP dual boot.