MN-700 and FTP Server issue

Archived from groups: microsoft.public.broadbandnet.hardware (More info?)

I just upgraded from an MN-500 to an MN-700 and run an FTP server on one of
the computers behind it.

I have DNS pointing to my IP at home and connect to the FTP site using it.

When I am at home (on the MN-700's network) I can access the FTP server via
the private address just fine without any issue. However when I am outside
of the local network and attempt to connect to my FTP server either by my
domain name or it's IP it no longer functions.

The connection is made, however I am unable to retrieve directory listings
and such.

I have done persistent port forwarding for port 21 too x.x.x.200 which is my
FTP server from the outside into the network.

The machine that is running the FTP server is Windows XP Pro SP2(RC1) (this
issue was there also before the upgrade to SP2).

Anyone have any ideas? I know on the MN-500, there was a firmware updated
that fixed the exact opposite of my problem (which was name resolution on
local loopback) however I am unable to find any firmware updates for this.

Any help would be much appreciated.