Comment 10 for bug 692189

Spoke with the Unity guys, this bug has to do with focus prevention and the window manager in use.

The classic desktop uses metacity and the window focus prevention there isn't customisable, if they use compiz/unity however then they can use ccsm to change the level of focus stealing prevention, its in the general tab.

But really as Sebastian pointed out if there are user events after the click the application should get the focus so therefore the bug either lies in rhythmbox for not using the right timestamps or compiz.