Most of the time I receive incoming calls for few seconds, then it shows as missed call while my caller listens full ring, leading them to thinking that I didn't pickup the call. I checked all the settings but couldn't find anything. This happens especially when I connect 'vodafone' sim card. I didn't have this problem with other sim cards. My handset is Samsung Galaxy 3 (GT-I5801).
remove true caller or similar app from ur cell, restart the phone it will be ok...tried my self.