I want to update my iPad 2 from 04.10.01 to 5.1.1 so I can use iCloud. My iTunes are up to date and I can update apps but when I try to update or restore the iPad, it works for about 5 minutes and then comes back with a message "the iPad could not be restored. This device isn't eligible for the requested build". It shows no specific error code. It's a wifi/3g model but I have never jailbroken it, it just worked with other SIM cards so I assumed it was unlock when purchased in the US. I'm trying to update on a MacBook Pro.