Brad,
We have the same "no service" problem on Lake Hartwell in certain spots. It's 
a bit of a nuisance, but then, sometimes it's nice to be out of range. The 
cell phone antennas are not meant for the small pocket phones. Remember when 
every car had an antennae.........those phones are usually used on boats and 
put out a more powerful signal which might improve your call reception. 

Rummy