I’ve just got my new shiny iPhone with Orange and am of course very happy with the UI, the apps and the amazing connectivity it gives you on the move. However, pretty rapidly after installing various apps I hit the problem of all installed apps closing immediately after opening them. Not good.
A long call on Orange tech support suggested a restore, which worked initially, but the problem soon came back.
A search across Google had various suggestions: resetting the settings, restoring, etc. But the one that actually worked was re-authorising my account on iTunes on my Mac (go to Store > Authorize Computer).
After almost pulling my hair out with a malfunctioning iPhone I was most relieved. It turned out I’d changed my iTunes account password on the iPhone but hadn’t updated this on iTunes on my computer. Once I’d re-entered the password all was fine.
Hope this may be of help to someone else with the same problem.