Getting an error saying that the app is not signed while syncing iPhone with your PC? I’ve been facing this error when I purchased some apps in iTunes and when I tried to transfer apps to the iPhone, it showed the error message like “Application was not installed on the iPhone because it is not signed. I tried almost everything from clearing the iTunes data to de-authorizing and then re-authorizing my PC. Nothing seemed to work though. I then noticed the recent changes that I made to the PC and figured it out.
The problem is most likely caused by the Firewall that you may have installed. In my case, it was ZoneAlarm that was not letting the app to sync with iPhone. I uninstalled the ZoneAlarm and it worked well. I was able to transfer all the apps without facing any error.
So, try tweaking or uninstalling your Firewall if you get to see “app is not signed” error.
lola says: 
David 
Nu_iPad_user 
philip 
Llewellyn 
Dave 
Eric 
nade 
NaN 
Bellona 
