Originally Posted by
jackal
...The suggestion to disable 3G is actually a very good one...EDGE, which the iPhone defaults to if 3G is turned off or unavailable, involves discrete transmissions on a given single frequency...Plus, most of the people around you on iPhones are on 3G, so by changing to EDGE, you're probably picking up on a connection that's much less burdened.
Thank you for the tip!
I also have lots of trouble with 3G at JFK and in Manhattan (iPhone and USB modem, both accounts are ATT), so I will try this next time I'm there.
The symptoms are the same...good signal, "connected" but no data comes in or goes out.