Bridging? - Two LAN's

[cheesyboofs]

Hi, After some pointers,

I have my LAN configured like so http://www.cheesyboofs.co.uk/home.htm I wish to break the trunk between the two switches. So I enabled a spare gig NIC (OPT3 - re0) and then plugged one switch in to it and left the other plugged in to (LAN - re1). Under the new NIC configuration I told it to 'bridge' with the LAN interface.

On applying the settings it all seemed to work, both segments had internet access (web browse) but on closer inspection the new LAN segment could not connect to the router's web interface or the BLUE wireless DMZ. I then went back and configured the gateway option under the OPT3 to 192.168.100.254 and this then fixed the Intranet connectivity problem but then broke the Internet connectivity for the new LAN segment.
I also noticed that I now have a OPT3 (LAN2) filter tab but what do I need this for if it is bridged with the LAN interface? surly it should be using the LAN filters if it is bridged!

Any Help  appreciated, have searched around but all I seem to find is references to making your firewall transparrent.