Since changing plans [for more minutes, free weekends, etc] I have been
plagued by multiple cut offs while traveling.  I can always reconnect upon
callback immediately after a cut off.  It happens any time day or night,
without any apparent pattern geographically or time-wise.  It has been
described to me as a unfixable problem while "switching towers".  I don't
buy it.  On the old plan I had no such problems while driving coast to
coast.  I still have the same old phone.  What's the real problem?  How to
fix it?