The Behaviour for Front Row on Leopard is hardwired, because:

- you can't change ratings of the current song anymore as it's now 
Front Row itself playing back these tunes, not iTunes (thus it's not 
possible to detect the currently playing song or change its rating - 
the new Front Row does - other than iTunes - not offers any APIs for 
this)

- it's no longer possible to put anything on top of Front Row. Thus, 
quite a lot of people did press the menu button long and opened the 
Remote Buddy menu. That menu, however, is overlayed by Front Row, so 
users could only see it after quitting Front Row, sending me a lot of 
complaints that "Front Row support doesn't work", when in fact it 
works very well, yet the new Front Row doesn't allow any windows on 
top of it.

So, while under Tiger you'll be able to customize the button mapping 
for Front Row as you used to, it's been disabled for Leopard since 
1.8.5 due to the usage problems users experienced due to the changes 
in Front Row.

The only thing I did not think of when doing this change was that you 
may want to relocate the menu button. I'll see what can be done about 
that.

Best regards, 
Felix Schwarz