My partner gets calls from people who said that she just rang them and they missed the call.  Only problem is, she didn't call anyone!  I've seen it happen with the phone lying on the coffee table in front of us.

Currently happening on an iPhone4, but she had the same number on a basic Nokia and experienced the same problem.  Vodafone support says they need a bout 6 occurrences with time and date of the suspected call before they can investigate.

Any ideas would be most appreciated.