I have been struggling mightily with the iPhone 4. Most of my issues stem from problems with the proximity sensor. The screen does not shut off when making phone calls and my cheek ends up making the phone do all sorts of crazy things. Usually the phone just hangs up but sometimes it calls other people or sets off the alarm and other strange stuff right in the middle of a conversation. It happens often and drives me crazy!!<p>I just upgraded to iOS 4.0.2 via iTunes and called my girlfriend immediately afterwards to see if it made a difference. I had a 7 minute conversation with no problems...so fingers crossed.<p>How are your iPhone 4's working?