Hi, I can tell you that I came back from Oxford to Blackburn (Lancs) today and whilst my old company mobile phone had full 02 signal strength pretty much all the way homw, my personal iphone 4 lost signal at about 1.30pm and still can't connect. It seems to be the type of handset you have rather than location. 210 miles along the m40 and m6 and it was the same all the way. A bit like the Blackberry incident last year possibly?