Hey guys, I have an iphone 4 that has an official carrier unlock through AT&T. i currently use it with t-mobile but today i noticed that the phone was no longer receiving calls. it could place outgoing calls and send/receive text messages but incoming calls would be directed to voicemail. i decided to restore the phone completely (latest firmware) and set it up as a new phone (not from a backup). after doing so, all functionality was restored, and the phone could once again receive calls. after restoring, i decided to disable cellular data and 3g in the settings but as soon as i did that, the phone would once again refuse to receive calls. upon re-enabling the two, the problem went away. my question is, is this a bug? as far as i can remember, i have always had the cellular data and 3g disabled since i have no use for cellular data. after not receiving calls for the last week, i became a bit suspicious. the only changes to the phone are the updates to the carrier settings, which i always allow. quite troubling, as now im unsure if i missed some important calls..