ipv6 / rtadv problem

Hi,
I am trying to get a -CURRENT box to get an IPv6 address via RTADV, however I am not having any luck.

I have tried the following in rc.conf :-
ipv6_enable="YES"
ipv6_gateway_enable="YES"

ifconfig_em0_ipv6="RTADV"

(the last one I haven't seen before but it didn't seem to have an effect anyway)

ifconfig shows..
em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
	options=219b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4,WOL_MAGIC>
	ether 00:25:90:32:09:1e
	inet6 fe80::225:90ff:fe32:91e%em0 prefixlen 64 scopeid 0x2 
	inet 203.31.81.43 netmask 0xffffffc0 broadcast 203.31.81.63
	nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
	media: Ethernet autoselect (100baseTX <full-duplex>)
	status: active

I see rtadv packets on the network :-
12:50:46.444380 IP6 fe80::204:61ff:fe79:276f > ff02::1: ICMP6, router advertisement, length 56

Other hosts can obtain a prefix just fine. This is the only 9.0 one, I have other FreeBSD boxes but they are 8.x ish.

--
Daniel O'Connor software and network engineer
for Genesis Software - http://www.gsoft.com.au
"The nice thing about standards is that there
are so many of them to choose from."
  -- Andrew Tanenbaum
GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C