My 928 has had a very odd issue when receiving picture messages for the last couple of weeks. When somebody sends me a single picture message, I will never receive it. However, if another picture is sent to me shortly after the first, I will receive the second picture and any more that are sent within a few minutes of each other. After some time, my ability to receive pictures "turns off" again and the cycle repeats. I am using the default messaging application within Windows Phone. Third party apps that use data such as WhatsApp do not have this issue. I hoped this was some kind of network issue, but the problem has persisted. Does anybody have any thoughts?