I have a jailbroken iPad 2 with ios 5.0.1 and I downloaded keynote from the internet. I tried to open it with itunes but it said that I had to register the computer to use the app, and it wanted me to log in with somebody else's email to do so. So I used iexplorer to transfer the ipa file directly to my ipad and installed it. The app didn't work and I removed it, but after that every time I try to sync my ipad with itunes it says my computer is not allowed to do that and I have to autorize it using the apple account that was regitered with the keynote I downloaded. It's like all of a suden my ipad became personX's iPad. If I choose to sync without autorizing the computer, iTunes says that all my apps will be erased. Please, somebody help.