We have just released a new version (v1.5) of our app on AppStore, this version was built using Xcode 4.6 using base SDK 6.1, supporting iOS 5.0 as minimum version. Now the problem is that iOS 7 users are unable to install the latest version (v1.5), however they can see 1.5 version on AppStore but when they install it they get 1.4 version.
Note: We submitted this app using Xcode 5.0 as Xcode 4.6 just got stuck in the middle...
Unfortunately the issue was sporadic, it happens with those users who use "App Store" mobile app to install our application. App Store displays latest version in the App-Store app but when they install it they get a previous version on their devices. Then again if user launches "App Store" he is able to upgrade to the latest versions. This issue doesn't effected our existing customers but the new one (those who have deleted the app from their device also experienced similar issues). We had a long conversation with Apple on this issue over emails, finally they admitted that it was due some problem at their end.
Now it is fixed for our app and we no longer have this issue for current release. I hope this post will help to someone having similar problem.