Mine seems to do it every few hours, it seems.. A reboot will fix it usually immediately, but it will switch back to 3G signal by itself after a "while." And I have FULL 3G signal where I am when it works. It's weird, because my phone will show EDGE, while my wife's iPhone will show 3G. A reboot fixes it, and BOTH phones will do this intermittently. And to clarify, this is in the same location, so we're not moving through different area... What's going on here? Is there some bugginess at work?