IPv6 problems with 6.2-RELEASE ?

[Pete French]

I have a network with a 6.2-RELEASE machine as a gateway to
the outside world, and on the inside three machines hung off it,
running OSX, XPx64 and 6.2-RELEASE as well. The gateway machine
NATs the internal network under Ipv4 and runs IPv6 via 6to4. It
has routing advertised on the internal network.

This *should* work - the OSX machine gets an IPv6 address and runs
fine. The Windows XP x64 machine also gets an IPv6 address, and
though it has problems with some wwebsites, it also basically works.
The only machine which refuses to work is the FreeBSD machine, which
refuses to acquire an IPv6 address!

I find it very opuzzling, as this has worked in the past, and also
the one machine I nwould have thought I would have had no problems
with would have been the FreeBSD box - especially as the gateway machine
is running an identical OS!

I am not even sure where to start debugging this - how can I make the
interface try and get an IPv6 address whilst watching what it is doing ?
Has anyone else had problems like this ?

-pete.