I can't speak for Handcent, as I was using Chomp and getting the problem. I have uninstalled Chomp and I'm just using the factory messaging app and it works great for me.
Same problem here but with a twist. I can originate text messages or reply to them to everyone on my contact list except one. My wife. She and I both got Samsumg Moment phones yesterday and no matter what I do, I cannot reply to her text messages without receiving that error message. She can reply to mine just fine. She had been in my contact list without the area code but I changed it after we got our new phones to add the area code.
I am a complete noob when it comes to text messaging and have no idea what messaging software is being used except whatever came with the Moment. I need help. Do I need to do a factory reset or what?
i have the same problem as John... I can text anyone in my contact list and not have a problem but when texting my wife i have to go to my contacts and act like I'm starting a brand new thread to get it to send anything to her. It will work a few times but it will eventually drop the area code and send me an error when i reply.... very frustrating... I also tried clearing out my contact storage and resyncing, deleting all of the messages, and verified that i had the 10 digit number in my phone and it still drops the area code... my wife has a palm pixi if that helps anything