My phone was sitting on the table next to me and vibrated, signalling a text. But when I pulled it up, the "from" number was my own. I checked out the message details and it said "unknown sender". It looks like it was trying to download an MMS message but was failing so the message would say "message not found" and I would have a notification in the dropdown menu that said it can't download and to update my APN settings. This happened about 6 or 7 times. I've deleted all the messages, thinking that would stop them from continuing. I haven't received any more since. Help???