Hi there,
I have the same problem but with a digital ISDN line.
Like above I enabled group divert on one of the handsets to divert all calls to an externational number, by entering a 9 and the number. Unlike above not phones are in Group 1 as we have two many phones for one group so they are in groups 1, 2 and 3 and I enabled group divert.
But when calls arrive the phones continue to ring and not divert to the external number...
Any help would be greatly appreciated.