Wirelessly posted (BlackBerry8300/4.2.2 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102)

I have loved the unit while using it in LA. I flew into JFK last night,tried the unit thru a 20 mile taxi ride thru open skies to my destinatin.all software says a"signal too weak for a reading"I'm even on a roof of a high rise right now.same thing. Anyone have any thoughts on this. I'm mystfied. Nav,google,bb maps all get weak signal.