Problem With Proxy over Routers (NT)

I have a WAN with two sites, the servers are on one side along with a number of workstations and a number of workstations are on the other.
Side A (10.0.1.xxx)(Gateway 10.0.1.10)
Side B (10.0.2.xxx)(Gateway 10.0.2.10)
Now before dialing the internet on the RAS server it can be contacted from either side. When The Internet is authenticated and the IP addresses (Dynamic) are set, I can only contact site A.

When running IPconfig it shows the gateway as it is supposed to be but contact accross the gateway is not achievable without dropping the internet connection.

So somewhere along the way it is getting confused about which gateway is which, i.e. I think it is trying to contact site B over the internet gateway.

Odd one….any ideas?