Similar problems staying connected with my BMW 5 series Handsfree. It will connect work for a while, and then randomly when I get a call or place a call it suddenly disconnects from the BT, but caller is still on. It does not happen all the time, but today it happened 4 times while I was driving on the freeway. Sometimes it re-connects, sometimes partially - so only dial works, sometimes only audio, and sometimes audio is terrible. I never had a problem with 3GS. This is very frustrating and dangerous. I have reported similar connection problems with Apple, and nothing yet works. My next step is to have them replace the Iphone 4. I doubt it will make a difference, but its possible that the radio in the phone 4 is slightly off frequency and that could cause these types of problems.