Trouble With Call Pickup Using RPID With Cisco

I have a Cisco 1760V with FXO ports hooked to POTS lines talking SIP to Asterisk 1.8.15.0.

imagining in extensions.conf:
exten => 1,1,Dial(SIP/121)
exten => 2,1,Dial(SIP/121&SIP/122)

When a caller dials extension 2 /and/ I have
trustrpid=yes
generaterpid=yes
sendrpid=yes in sip.conf and I use the pickup exten, the caller is disconnected.

see: http://jeremy.kister.net/tmp/ast/group-with-rpid

if i set the rpid generate/send = no for the cisco peer, the user is connected. see: http://jeremy.kister.net/tmp/ast/group-without-rpid


calls to exten 1 work regardless of rpid settings.

i have replication configs at http://jeremy.kister.net/tmp/ast/

Can someone help me determine if this is a problem with asterisk or ios ?