LS670 & error 16 when I'm away from my Airwave

[JHILL110]

Greetings all, I'll try to keep this short.
I live in an area with crappy signal. Sprint sent me an Airwave gratis and everything was fine until I upgraded my phone to the Optimus S. It works great at home but when I leave for any length of time and try to make a call I get error 16... blah blah blah.

I hang on and a CS person will come on, ask me ALL the same questions and do a "CHLR" refresh for me. Cool. Yep. I got pissed after the 2nd time and had Sprint send me another phone... Yep... Same crap. I'm disabled and don't go out often but when I do I like a working phone. At home it's a great phone!! Love it. My first Android.

Sprint tech support has no solution... Tried many things.

I'm hoping someone in this forum can help me with some sort of work around (unlike sprint) for this issue.

Any ideas would be greatly appreciated.

Thanks for any help.