[plug] Games firewall problem?

[Kai]

Howdy folks,

I've been trying to connect to a local games server at 
loki.3fragsleft.net:27019 and another (not so geographically local) at 
thor.3fragsleft.net:27020
Connection to those ports on those two servers fail.
I have a friend in Broome who has the same firewalling rules as me, he 
can reach both server, I can browse, email and download from these 
servers but Server Query tells me the servers are unreachable and the 
ports are closed.

I have another friend who lives in Perth who can also access the servers 
through his firwall - his kernel has been recompiled and I think he has 
a slightly different ruleset.

I have rebooted this Windows machine into Linux (6.2) and run NMap which 
tells me ports 27019 and 27020 are closed, so it appears like a firewall 
problem and not a problem with Windows (?)

My Linux firewall/server is this:
Kernele 2.2.14 - not recompiled, what comes with Red Hat 6.2
NE2000 compatible 10 Meg ISA NIC
This is what my friend in Broome is using for IPChains rules, I have the 
same set:

## Flush any current ipchains rules
/sbin/ipchains -F input
/sbin/ipchains -F output
/sbin/ipchains -F forward

## Accept packets local packets, masq internet bound packets
/sbin/ipchains -A forward -s 192.168.0.0/24 -d 192.168.0.0/24 -j ACCEPT
/sbin/ipchains -A forward -s 192.168.0.0/24 -d 0.0.0.0/0 -j MASQ

Windows/Linux machine:
Kernel 2.2.14 - not recompiled, what comes with Red Hat 6.2
Intel Pro 10/100+ PCI NIC

I have a 5 port Edimax hub between the two.

Anyone have any ideas what might be happening? or need further info?

TIA !

Kai