Question : Routing between two networks, ISA gateway

Please point me in the right direction if I'm not posting this right but here goes...  
I'm currently administering a small office network, roughly 4 servers and 50 machines.  
The four servers are as follows 2 DCs, 1 Exchange, 1 ISA server.  
All the servers except the exchange server are multi homed (I just started this job and inherited this mess).  
There are two internal networks, 10.8.x.x is our main internal network which we use for clients, printers, etc, and there is another internal network 192.168.x.x which the servers are multi-homed to and this network also has our watchguard firebox and router.  
We are using the ISA server as the gateway with two nics with the addresses of 10.8.2.3 (internal side) and 192.168.10.5 (external side).  
We also have two small remote sites (5-7 users each) with an active VPN connection to our firebox, but the traffic is not being routing from the 10.x network to the 192.x network in any way so it makes it impossible fo rme to manage any of the remote machines without logging onto the ISA server and in addition they have problems communication with the domain becaus of this.  
I'm more of a deployment guy, so help steer me in the right direction with what I need to do to get traffic routed between these two networks?  
RRAS is install on the ISA server but doesn't appear to be doing a whole lot.  
Thanks in advance and let me know if you need any more info!

Answer : Routing between two networks, ISA gateway

Excellent.

Please provide the output from 'ipconfig /all' AND the output from a 'route print' on a working machine (that you can scan OK) and the same again from one that is not working as expected. lets see if we have a difference in gateways, static routes.

The next step will be a process-walk - we are getting there :)