I'm using a keyboard with Boxee, so I dont know what remote control button backspace relates to, but I'm finding that backspace takes me back one menu
when you get to the screen of an album's track list with the play and last.fm buttons above it, on that screen the delete key doesn't do anything. The only way to get out of that screen is to use the esc key.
I would expect backspace to take me back to a previous menu like it does on every other menu and screen in Boxee.
I'm using Boxee on (X)ubuntu 8.04.