My wife and I got new Optimus S phones a few weeks ago and we both are having the same problem. We can't text each other. When we do we get an error message 9230 saying that it needs to be a 10 digit number (we are both in the same area code). We can text other people but we can't text each other. We've called Sprint's customer service and they told us to hard wipe our phones. It worked...for a few days before returning. I called them back and they said it's a known issue and the rep said the solution is we need to hard wipe our phones every few days. Perhaps the dumbest thing I have ever heard. I've looked through the forums here and found a few suggestions from threads going back to last summer like clearing the data from the dialer and dialer storage with no effect. I can't believe that this is a problem going back that long that Sprint knows about and their only suggestion is for someone to just keep hard wiping their phone every few days.