Adtran 7100 with (3) 712 phones 1 CO/pots line R11.10.1.E - Pots line is programmed as a shared line on all the phones. Customer complains calls ring in and sometimes you cannot answer it. They describe it as the phone is locked up. they pickup the handset and it just keeps ringing. If they hit buttons nothing changed. Of course I cannot duplicate it when I'm onsite. I trust it does happen.
It's the latest version, I'm not on site right now to give you the numbers, but our tech support checked that with me, also I verified that with the current download available from adtran support site.
Jim, you'll probably need to open up a ticket with Tech Support, as this issue is likely to be more complicated than something we can work over the forums. Thanks