My Iphone Pandora app will not rotate to landscape mode now, Any idea how to fix?

I have tried to reinstall it
I have did the new ios upgrade
I made sure portrait lock was not on the music settings, (the native music player works when you rotate it)

My last resort is to back up my iphone and reload it, I really don't want to do this, any options that I'm overlooking?

It is an Iphone 4s and is now at IOS 6.0

Turn the iPhone landscape…
Its not rocket science