I wonder if anyone else experiences this fault? I have a recurring but intermittent fault in iPhone 4 (4.3.3). Call duration does not seem to be a factor, nor does power state of the battery, nor does calling party (incoming or outgoing are equally susceptible. Call cuts out - neither party can hear anything Call does not "fail" - no failed call triple beep Call cannot be ended from the keypad - phone requires full power-off/on reboot Windoze style. Now, this used to happen on my iPhone 3GS too, but this is a brand new phone, with a brand new SIM, and was "built" as a new phone rather than a restore from backup. Any ideas (apart from getting shouty with O2)?