You may want to check software revision. They changed some internal codes between versions. The user manuals of the phones may list the earlier software version code.
If you are using 4 digit extensions, you may need to add the same leading digit to the 3 digit code.
Also, you may want to step through Flash 52 in programming to confirm the code you are using is in the pre-programmed codes.

Last edited by A6; 10/12/12 07:34 PM.

Tip and ring, the work of the devil!