FreeBSD 5.1-p11 mIRC XDCC send resume won't work

Hi!,

I try to configured my natd to be able to do a XDCC send resume with the
mIRC Client on a Windows XP computer.

I run a FreeBSD 5.1-p11 Server with Natd and IPFW, behing a Windows XP
workstation with mIRC 6.12

I add those rules into my /etc/natd.conf

dynamic yes
use_sockets yes
same_ports yes
redirect_port tcp 10.0.10.100:113 113
redirect_port tcp 10.0.10.100:8000-8005 8000-8005

10.0.10.100 ( IP of my Windows XP client )

And I configure my mIRC to used ports between 8000-8005 for xdcc send.

The redirect port works, but not the resume, why ?

I also desactived all the firewall rules.

And when a connect the Windows XP workstation direct to the Internet
connection, ( bypass the FreeBSD Server ) everything works.

Anyone have an idea, where's the FreeBSD-natd-IPFW problem ?

thx

Seb