The last time it wouldn't update an app, I could see in the app store and on the website that my app had a new version, but no matter what I did, I could not make it update the app. I don't know what I was doing "wrong", but I think if I couldn't figure it out or make it happen, there's something very wrong with either the app or how it's "supposed" to work. Neither of which is an acceptable user experience for me.