I have a stock ipad 2. I have upgraded to ios 5.1.1 and also subscribe to a cellular plan. I just noticed that the "cellular data" tab is missing from settings. I understand that it is not under the "General" tab anymore, but it is also not under the "Brightness & Wallpaper" tab. I have restored to factory settings and reinstalled...still not there. Not sure where to proceed from here. Any help is appreciated....Thanks