Keyboard “Special” function keys stop working in UBUNTU 9.04

When I upgraded UBUNTU 8.10 to 9.04 the special function keys I had programmed stopped working. After a fresh install of UBUNTU 9.04 from CD, and following the procedure I normally use to configure the keys they still don't work.

Basically, I create an xmodmap.conf file and add a keysym for each key that has a key-code but doesn't have a keysym entry. Then, I configure xmodmap.conf to load on boot-up. Next I use metacities global_keybindings to bind the keycodes and a its keybinding_commands to enter the phrase that starts the program I want the key to activate.

Does anybody know why this procedure no longer works?