Here's the situation, my sister has an AT&T plan from back in the day, and she has a voice and text plan only. She has _NO_ data tied to the account. I gave her my old iPhone 4 last year and it's been working fine for her on iOS 5.x. She uses the data portion with Wi-Fi only at the moment so that doesn't bother her with not having a Data plan. Just recently when I gave her my 4S with iOS 6 on it, she is no longer able to get MMS text and any group text that included non iMessage users fail to send to her. If everybody is on iMessage, then it works fine. These are the two case scenarios that fails to work. Unfortunately when I took back the iPhone 4, I updated it to iOS 6 as well so now we're stuck with this issue. Anybody have any ideas?