How to disable firewall on 3Com OfficeConnect ADSL

Hi all,

Can anyone advise me how I go about disabling the firewall on the 3Com officeconnect ADSL router? It's the 3CRWDR101A-75 as suggested in this thread: http://bbs.adslguide.org.uk/showthreaded.php?Cat=&Board=dslrouter&Number=2880904&page=&view=&sb=&o=

The problem I have is as follows:

I have a block of 5 IP addresses routed to me. My router has the first IP address in my range allocated to it (x.x.x.169). I have a server on x.x.x.170 that acts as my mail server.

I have set the Firewall Level to 'Disable' under Firewall -> SPI in the web configuration tool and also disabled NAT at Advanced -> Security.

After doing this, I cannot ssh or make connections to port 25 of my server.

The next thing I tried was setting up the DMZ hosts. I added the following entries :
x.x.x.169 -> x.x.x.174
x.x.x.170 -> x.x.x.170

I really didn't want to send x.x.x.169 to anything, but it would not let me leave it at .0, so I picked a host that is down right now.

After doing this, I still can't connect to port 22 or 25 on x.x.x.170 from the Internet.

This is definitely a configuration issue with this router, as this worked fine with the netgear, so all hosts are correctly configured.

Any advice would be much appreciated!