Texts going to wrong phone in account
We have 5 iPhones in our family account. Recently, person 1 will send a text to person 2, but the message will show up on person 3's phone. Oddly, person 3's text display show the message as if person 3 sent it! The messages often go to several of the phones, so it's impossible to tell (without asking) who actually sent the message. Any ideas?
iPhone 4, iOS 5.1