OK, I take a 'backway' home a lot and it seems like I'll have 3 or 4 3G bars and soon as I go to make a call it drops to nothing and won't connect. As soon as it fails or I hit end call... it pops right up 3 or 4 3G bars again. Lather, Rinse, Repeat... as soon as I go to make a call it won't. This also happens when I'm up at my cabin.

Can anyone explain this?