He means the two SA's for the VPN's are conflicting with each other. But you were not even clear as to what type of VPN you are using. Is it IPSEC or GRE or neither? Also, you only mention the internal addresses. Are you using NAT? (you must be, since 10.xx.xx.xx won't route on the internet!) Since you MUST be using NAT, the problem is likely that the VPN server see's all tyhe machines trying to connect as coming from the same IP address. That won't work. Each outgoing VPN connection to that VPN server must come from a different external IP address. That answers why only one PC can connect thru the first gateway at a time. This is to be expected. The work around would be to do a site to site vpn rather than a PC to site vpn. (do the vpn connection on the gateway, not the PC)