Hi joebacon,
Yes those dip switch settings are correct. The reason this is done is to split the frequency range in to 2, an upper and lower range. The reason they are getting static or losing the ability to transmit or receive is probably nothing more than the range of those base stations, which is limited. About all you can do is insure the base stations are in a centralized area and that the antennas on the base stations are on a 90 degree angle from the base itself. Is this something that has just happened recently or has it been this way since the install?
"Hope for the best, plan for the worst