I have a Dell XPS M1530 with Xubuntu 12.10. My Fn + Up Arrow and Down Arrow for adjusting screen brightness work perfectly fine, but using the Fn key with the function numpad does not work. These used to work with an old version of Ubuntu or Fedora a few years ago, but I can't remember what version(s).
Actual keys:
7 8 9 0
U I O P
J K L :
M . /
Fn numpad keys:
7 8 9 /
4 5 6 *
1 2 3 -
0 . +
