Pete,
I don't know about signal issues in the US, but can maybe help you configure your browser. I bought a Nokia 3G phone in Thailand and had to get my browser to work in Canada. Calls to my service provider was a WASTE OF TIME.
Nokia web site had a configuration tool... I had to dig for it and it took me a few tries to get it right, but Nokia sent me all the cofiguration settings by SMS.
The charges were outrageous, so I stopped using it, but NOKIA was great and the website and software top notch.
Good Luck!