Greetings,
 
I've been reading posts from your lists for the last hour or so and have finally stumbled on a
solution to some people being unable to forward ports to servers on their LAN.  This post in
particular resonated 
 
http://m0n0.ch/wall/list/showmsg.php?id=110/59
 
All I was attempting to do was to forward SMTP traffic to my mail server.  I tried various sets of
rules was unable to telnet on port 25 using a remotely controlled server on a seperate network.  My
logs even showed allowing the connection while I saw the connection timeout.  Finally, I used the
ping utility in the webGUI and was unable to ping the server on the LAN using the WAN interface. 
Frustrated, I then found it would ping my desktop machine, only 2 ip addresses away from the server
I wanted it to ping!  The only difference between the two machines was that I had been using the
internet through Mono where as my server was pointing to my retired router (off the network) as it's
default gateway...I changed the gateway, fired up a browser to test the server's connectivity and it
all just started working!  Does this make any sense?
 
thanks,
Bash Ahmed