Fresh copy of 2.4.19 and iptables 1.2.7a with patch-o-matic and used the z-newnat and h323 that comes with it.. fixed the newnat patch which couldn't load. add 2 lines to a ip_conntrack.h file and it worked fine

Then added these rules
$IPTABLES -t nat -A PREROUTING -i $EXTDEV -p tcp --dport 522 -j DNAT --to 192.168.0.11 # H323
$IPTABLES -t nat -A PREROUTING -i $EXTDEV -p tcp --dport 1503 -j DNAT --to 192.168.0.11 # H323
$IPTABLES -t nat -A PREROUTING -i $EXTDEV -p tcp --dport 1720 -j DNAT --to 192.168.0.11 # H323
$IPTABLES -t nat -A PREROUTING -i $EXTDEV -p tcp --dport 1731 -j DNAT --to 192.168.0.11 # H323
$IPTABLES -t nat -A PREROUTING -i $EXTDEV -p tcp --dport 8080 -j DNAT --to 192.168.0.11 # H323

insmod ip_conntrack_h323

insmod ip_nat_h323

Regards Tim