Can't remove function key mapping

[ljcl]

Hey guys.

Earlier I remapped the function (fn) key to 'show desktop'. And I can't seem to remove it.

Now when I want to use the function keys I have to use them blind as the windows disappear when I try to use it!

I've reset all keyboard shortcuts in Keyboard. I've made sure that "show desktop" under mission control is not set to function either.

Any suggestions would be greatly appreciated!
Thanks.