RED with multiple subnets?

Hi Everyone,

                   This is probably a pretty basic question so don't beat me up too much...  Our main office has a UTM and uses 10.0.0.x.  I just got a branch office set up with a RED50 ( Standard/Unified) using 10.4.0.x.  They have a card access controller that was set up to use 10.100.1.10.  How do I go about configuring the UTM so that someone on 10.0.0.x or 10.4.0.x, can access that controller at 10.100.1.10?

So far I've done the following...

I went in to network definitions and defined the 10.100.1.0/24 network and bound it to the RED.

I defined a host with the 10.100.1.10 IP.

Under Interfaces -> Additional Addresses, I added 10.100.1.10 on the RED interface.

I added firewall rules to allow any traffic from and to 10.100.1.0, 10.0.0.0, and 10.4.0.0.

Currently, I can't ping 10.100.1.10 from 10.0.0.x but if I go in the the UTM -> Tools -> Ping, then I can ping it.  (Use closest route uses the RED interface.)

Help me wise Astro/Sophos gurus.  :)

 Thanks,

             Ben