The antenna problem has nothing to do with signal strength, I'm pretty sure it's a design flaw. I say this, because a few days ago, I tested this on my friend's iPhone 4 at our house... There is an AT&T cell tower within line of site, less then 500ft from our house, so there is no way we have weak signal, as every phone I've ever had in this house, always had full strength. And from where I tested this, you could see the tower through the window...
Anyways, my friend couldn't reproduce the problem, but I simply touched my finger to the spot on the antenna, and after 10 seconds, the phone lost all 3G signal, then switched to Edge, with 1 bar, sometimes zero. Removed finger, and within 10 seconds, got full bars on 3G.
I'm pretty sure this problem is more tied to skin capacitance, then weak signal strength, as my hands were warm and moist, and my friend's hands were usually cold and dry.