irc resuming through natd

[cedrick.gaillard]

hi,
 
it's impossible for me to do irc resuming through may freebsd gateway.
i was on freebsd 4.7 and i am now on freebsd 5.2.1 current and the
problem persists on both versions.
 
someone have a good way to do irc resuming?
 
here is my natd.conf :
log yes
log_denied yes
use_sockets yes
same_ports yes
interface xl0
punch_fw 10000:20
log_ipfw_denied yes
 
i use ipfw
if my other computer is connected directly on internet, it have no
problem.
 
Thanks
cédrick