I am running same app in iOS6 and iOS7 which has NavigationBar.It runs well on iOS6, but in iOS7, all view is little bit up like it is not considering the Navigation bar at all.
In iOS 7, view controllers use full-screen layout. it is mentioned in iOS 7 UI Transition Guide
if you want change the layout use edgesForExtendedLayout property
example:
if([UIViewController instancesRespondToSelector:@selector(edgesForExtendedLayout)]) self.edgesForExtendedLayout=UIRectEdgeNone;