Comment 6 for bug 32917

Are you sure totem has this issue too? I've been seeing this for years (and still on dapper) and totem picks up play pause key changes straight away whereas rhythmbox does not...

Be warned! totem only responds to keybindings when its window is focused (unlike rhythmbox that always responds whether it unfocussed/minimised/hidden etc.). If rhythmbox is open it will steal the pause button keypresses before totem can get hold of them.

This can be demonstrated by changing keybinding when both totem and rhythmbox are open. Assuming totem is focused it now able to see the new key because rhythmbox has not grabbed yet.