Can’t Connect to Client Computer Using SBS 2003 Remote Web Workspace

I am having trouble connecting to a client computer using SBS 2003 RWW outside of the LAN.
I CAN access OWA, “My Company’s Page”, and I can connect using the “SBS Connection Manager” or VPN while outside of the LAN. I CAN connect to a clients desktop through RWW when I am ON the LAN, using another clients computer.
What is causing me to not gain access when I am outside of the local area network? I’d assume that the proper firewall ports are open because I can access the sever through remote desktop and I can connect to the server using vpn, or SBS Connection Manager with all of the clients listed with “mobile” rights.