Here is my circumstance. I work between UK and US at times. I have an ATV which I took to the UK and has been working perfectly here. I have two apple IDs, one for the UK store and one for the US store and predominantly use US one even when the UK. When I just updated to ver 5.1 all appeared to go well and I got to the screen showing the new features. Press to continue. I did and I saw a message stating my ID was only valid for the US iTunes Store. That is fine I thought. Now that was where my problems began and now ends. It now will not allow me to do anything. I cannot navigate. I cannot make the selection change from movies. It just appears not to want to do anything other than sit on the movies icon and even a forced reboot just ends up wig the same scenario. I guess I will have to get to work out his to reset to defaults as that may be the only way to get around this. This is a Bad Rotten Apple Upgrade!!!!!