AsteriskNow 3.0 (Asterisk 11 + FreePBX): Calls to Ring Groups Go To Voicemail; Ideas?

New installation from AsteriskNow 3.0.0 with asterisk 11 and Freepbx, running Digium D40 and D70 phones.

UPDATE: We’ve confirmed the same behavior on our standard Polycom 550 - so it’s not specific to the Digium phones.

Direct-dialed extensions work fine, but extensions in RingGroup won’t ring - dialparties.agi apparently removes them from the dialstring pre-emptively:

dialparties.agi: EXTENSION_STATE: 4 (UNKNOWN)
dialparties.agi: Extension 2010 has ExtensionState: 4

What can I do? Any extension that is actually registered and
available is being removed, then the ring group drops through to
’Destination if no answer’. I’ve got a town hall waiting for this
system and I’ve never seen this problem before. Googling finds a few people with this problem, but I’ve not found a solution posted
anywhere yet.