There was an update?
When I first got my S4, it was a PITA that I couldn't control my Home Theatre. It took several attempts powering up my Samsung TV and once I turn on my Denon Receiver I can't turn it off and can only control the volume.
I reseted the app several times and even gave up on it. Until Samsung upgraded a few weeks ago, I gave it another chance and everything went smooth!
I would try reseting the app.
