having problems with data on 3G on iPhone 4? Try this!
I have seen many complaints with data not working including myself. I first tried new SIM card and then reset networks settings. Didnt work. Restored as new. Still had issues. Got a new iphone 4. Still had issues.
So I called Apple tech support and the lady told me to go swap it again. I told her the odds of the exact same proplem being hardware is highly unlikely. She transferred me over to some high level tech support. After explaining my entire issue all over, he told me to call ATT and have them re-provision my data plan. I told them I already called but they said if they did, I would lose unlimited data. He stated thats not true but I needed to talk to tech support and not regular customer service. The Apple support could not call Att for me as they were having issues with making out going calls so he told me to make sure they re-provision the data plan and then keep my iPhone off all night until morning. Now I got on the phone with Att tech support and he stated at their level that they can reprovision the data plan. He also stated that to also keep the iPhone off all night as it initializes.
So I completed this last Tuesday June 29th about 8:30 PST and since turning on my iPhone Weds morning, I have not had any data issues in all the areas that I didnt previously with my 3GS. In fact, I dont think my data has got hung up once at all. This isnt guaranteed to work but its worth a shot and it solved my data problem with full bars of 3G.