Vine app for iPhone 5 won't record sound?

I used to have the 4S and it recorded sound on Vine just fine, but I just got an iPhone 5 and all I hear is static? The mute switch is NOT on, I can listen to people's Vines, but on my own there's no sound… Help? I've even had the switch on the left on audio while recording them and still no sound… Not sure what else to do?

Added (1). I figured it out, it was that the screen protector on the BACK apparently covered a microphone… Didn't even know there was a microphone on the back. But thanks for the help!

Well… From Apple's perspective, the only thing I can recommend that you do is just uninstall the app and the reinstall. Typically that fixes most issues with 3rd Party Apps. However if that does not work you are going to have to contact the people that made the App.