changing the decoder address

[AlvinPaul]

I am trying to establish a DCC controlled layout using a DIGITRAX ZEPHYR DCS50 command control.  I have purchased three BACHMANN DCC-EQUIPPED LOCOMOTIVES and cannot, using the DIGITRAX manual's proceedure for CHANGING THE DECODER ADDRESS, change the decoder address.  An error message telling me the DCS50 is not able to read the decoder appears on the DCS50's display whenever I try either on a PROGRAMMING TRACK or the main layout.
Please pass proper proceedures or other gems of wisdom regarding decoder address changes along if possible.
Thanks, P.D.

[jward]

in addition to trying the 1000 ohm resistor across the rails of the programming track, you can sometimes reprogram the bachmann decoders using ops mode, with the locomotive on the main track.