Have been using my 3G iphone since the day they were released back in July. I live in Chicago and am very familiar from daily use where in the city 3G dead spots are, where I bounce back to edge, etc. Since upgrading over the weekend to 2.2.1, the phone's connection to any data connection is erratic. I can be standing completely still and bounce between edge, 3G, and back to edge all while trying to load one page. In fact, if I'm trying to load a page while the phone is on 3G (full bars) it will immediately switch to edge as soon as data begins to flow. I just had my sim card replaced (per the other thread) with no change in behavior. Anyone else experiencing behavior like this, or do I just have a genius bar appointment in my future?