Hi I have a Blackra1n jailbroken/unlocked iPhone 3G. I have just finished my contract with 3UK and moved over to T-Mobile. When I first turn on my phone, turn 3G on/off or activate/deactivate flight mode, I often get very good 3G signal for a good few minutes. However, after a while, I fall down to GPRS for no reason at all, my 3G signal was fine so I don't understand why it does this. Any ideas? N.B T-Mobile UK use compatible bandwidths for 3G unlike T-Mobile America.