I recently upgraded from a iPhone 3G to iPhone 4. There have been two occurrences (that I know of) of very odd behavior: 1) Yesterday, I'm sitting at a restaurant having a conversation. Someone, we'll say Bob, calls my phone and I don't hear it ring. Somehow the phone answers on its own and Bob can hear my conversation which is occurring in real life through the phone. There was nothing else in my pocket with the phone. This type of failure happened twice, separated by hours, yesterday. 2) Today, I was talking to someone we'll call Mike over the phone while in my car and the phone was paired to the car's bluetooth system. Someone we'll call Fred called me. Without me becoming aware of it, the phone answered. Fred could hear my conversation with Mike but could not talk to me - if Fred spoke, I couldn't hear him. In reality, I'm not the one having these problems, it's my dad, but just to describe them easier, I'm did it this way. It wouldn't surprised me if he mashed buttons when he doesn't know what they do but I cannot understand which settings could ever cause these behaviors. I cannot think of ANYTHING which would cause these behaviors and would be interested in any explanations for what could cause these two incidents and how to fix them. This is very worrying, since the iPhone is effectively behaving as a "bug" and allowing people to hear conversations they're not supposed to without him being aware of it.