firewall on SBS 2003 not isa

I have three site connected via the Symantec security gateways, I’ve had to muck around with ISP’s and the main server setup for the connection to the ISP’s. I went from the gateways to a direct connection and then back to the gateways and now the other two site can’t connect to the server but can to other devices/computers. but I can setup a software vpn to the server and this will work but defeats the purpose of the VPN gateways.