It depends on what remote you are using as to if you edit the keyboard.xml or the remote.xml. You need to see if you remote is sending keystrokes or not.
Main - Intel E6750 C2D (2.66ghz)/Geforce 240
Bedroom - Intel E3300 C2D (2.5ghz)/Geforce 210
Guest Bedroom - Acer Revo 1600/ION LE
Test Desktop - Intel Q9300 C2Q (2.5ghz)/Geforce 9600 GSO