FTP server will not initiate DATA connection back to client

[freebsd at stateautomation.com]

I am running FreeBSD 4.9 RELEASE running the standard ftpd.  I can act as an
ftp client from the console OK, however when I try to ftp from a client PC
to the server running ftpd (which is running ipfw) the ftp server receives
the packet sent to port 21 and replies however it will not initiate a DATA
connection back to the client from port 20.  I had my client configured to
use ACTIVE FTP.  I have also tried PASSIVE without any difference.  I do not
have a firewall on the client and can successfully FTP to another FreeBSD
box.  
None of the rules on my firewall that deny packets coming back from the ftp
servers ipfw firewall are being hit. Does anyone have any ideas?
Regards, J.S