I have got an iPad 2 which currently has 4.3.3 on it. I tried to download 5.0.1 online and then restore the iPad using that file, but iTunes shows an error message. I don't want to update to 5.1, otherwise I would lose jailbreak. Is there any way I can update to 5.0.1? When I try to update, it says "the ipad could not be restored. this device isn't eligible for the requested build"