recent MFC code to 6-STABLE kills ipv6

My IMAP server used to work perfectly fine with IPv6 connections from
evolution.  Today, there was some MFCd code that has killed it.  I can
no longer log into my imap server with IPv6.  Investigating, I find that
the interface I have tied to stf0 will not respond.

I have

dc0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        options=8<VLAN_MTU>
        inet6 fe80::203:6dff:fe1a:b19b%dc0 prefixlen 64 scopeid 0x2
        inet 24.199.45.54 netmask 0xfffffffc broadcast 24.199.45.55
        inet6 2002:18c7:2d36:0:203:6dff:fe1a:b19b prefixlen 64
        inet6 2002:18c7:2d36:: prefixlen 64 anycast
        ether 00:03:6d:1a:b1:9b
        media: Ethernet autoselect (100baseTX <full-duplex>)
        status: active
sk0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        inet6 fe80::214:85ff:fe85:27b3%sk0 prefixlen 64 scopeid 0x3
        inet 10.0.0.1 netmask 0xff000000 broadcast 10.255.255.255
        inet6 2002:18c7:2d36:1:214:85ff:fe85:27b3 prefixlen 64
        inet6 2002:18c7:2d36:1:: prefixlen 64 anycast
        ether 00:14:85:85:27:b3
        media: Ethernet autoselect (1000baseTX
<full-duplex,flag0,flag1>)
        status: active
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
        inet6 ::1 prefixlen 128
        inet6 fe80::1%lo0 prefixlen 64 scopeid 0x4
        inet 127.0.0.1 netmask 0xff000000
stf0: flags=1<UP> mtu 1280
        inet6 2002:18c7:2d36::1 prefixlen 16


ping6 works for

www.kame.net going out my dc0 connection.
fe80::214:85ff:fe85:27b3%sk0
2002:18c7:2d36:1:214:85ff:fe85:27b3
2002:18c7:2d36:1::
fe80::1%lo0
::1
2002:18c7:2d36::1

ping6 does NOT work for

fe80::203:6dff:fe1a:b19b%dc0
2002:18c7:2d36:0:203:6dff:fe1a:b19b
2002:18c7:2d36::

I have ip6fw setup, but nothing is showing as denied.  This worked
perfectly fine up until today.

Sean