I have an iOS app that worked well on all devices in iOS 6.
I recently upgraded my xcode to version 5.0 and tried to build the same app for iOS 7 on an iPhone 5.
In your .xib file in Xcode 5, click on the offending control. Go to the properties menu on the right and click on the "File Inspector" tab. It is the tab that looks like a sheet of paper. On that tab, there is a section called "Interface Builder Document". Make sure "Builds for" property is set for "iOS 6.0 and Later". If none of the other fixes above have worked, this is likely your culprit.