I mostly text my girlfriend who lives in the same space. we are both on a "network extender" both have iPhone 4. for the last two months we have been charged for about triple the normal text messages. when I look at my online text records I see two messages sent at the same moment. and when she gets the text message their are two sometimes three copys. I have been on the phone w/ Verizon support for about 3 hours and several diff. times. they have done a number of things to resolve the issue but NO success so far. They did credit our accounts for the overage but the problem continuse un abated.