keyboard "Play" button only works if desktop controller has focus

I use Spotify but prefer a lot of things about the Sonos app (I use Windows 7 and desktop controller)--like the fact that it only has one queue. Unfortunately, Spotify integration with Sonos is poor, but I might live with that except for one thing. I use the "play/pause" button on my keyboard to turn on and off the music. For Windows Media Player, the old Zune/Groove apps, and the Spotify app, it works as expected--when I hit pause, it pauses, and the app doesn't have to have focus. But the Sonos desktop controller doesn't handle that keypress unless it's the foreground app. I'm a programmer, so I know when you say "it's only software" that doesn't mean it's easy... but this is so small I wish they would fix it!