My iPhone 4 (with Verizon) makes calls without any problem 99% of the time. However, when I try to call one friend of mine, it has been acting very strange. This is a recent development as before this weekend it had been acting normally. It now takes 30 seconds before it starts to ring when I call her. There is a lot of white noise type "static" before that. When she picks up, the static continues and there is a 5 second delay between me saying something and her hearing me and responding. It doesn't seem like much, but it does disrupt the flow of conversation. The static also occasionally garbles her words. She says that on her end, I sound "static-y and distorted". The strangest part is that when she calls me, all of these problems disappear. I have none of these problems calling anyone else, including people I know who live just a few miles away from where she lives. We like to talk a lot so this is very frustrating. What could be causing this?