It’s not a Graphics 2.0 issue. We dropped support for iOS 5 because of all of the hacks we were having to do to support iOS native things like GameCenter, the Camera app, facebook, etc. Anything that put up a portrait only dialog box would crash landscape only apps, so we were constantly having to hack around this iOS 5 issue.
If Apple does like last time, they will start requiring all apps to be uploaded against the iOS 8 SDK probably in February. When this happens, Apple will have officially killed off iOS 5.
The build that still supports iOS 5 is built with a version of Xcode that Apple does not allow submissions from any more.
Rob