Has anyone else had a problem trying to use a sim from a t-mobile mytouch 4g in an unlocked iphone? I unlocked an iPhone 3G and the sim I used to test was from a mytouch 4g, after unlocking I made a test call fine, then the phone would lose service and then regain service. Just curious if anyone else has ran into this? I held an att sim an the test sim next to each other and the contacts on the att sim were bigger than the t-mobile test sim.