I have had this problem for the last couple months. I have an iphone 4 (running 4.2.1 until last night when I upgraded to 4.3.3) and can receive MMS from everyone (that I know of) except for my girlfriend. She is on the same family plan and is using an iPhone 3G running 4.2.1.
She is able to send and receive MMS to and from others.
Does anyone have any suggestions or ideas on what might be causing this? I hope I gave enough details, but if not, let me know and I'll post more.
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