can't send/receive on 2 MS VPN connections

[timw2979]

I am trying to connect multiple computers in my office to a VPN server at a client's site. I can send and receive on one computer, but as soon as I connect another MS VPN client, the second computer can then send and receive, but the first computer can now only send and not receive.

-The client claims that they have tested this and they have no problems in their office.
-I don't know any info on hardware and software on the client's end.
-All computers in my office are using the Microsoft VPN client in the Network Connections of XP Pro.
-I've tried the same connection on a number of computers in my office and ran into the same problem.
-I've tried it using a Linksys BEFSR41 and also a Netgear FVS114 and have the same problem with both.
-Internet connection: highspeed cable through Comcast with static IP SMC 8013WG modem.

Does anyone have any ideas on what might be wrong?

 

[timw2979]

Problem solved. The problem ended up being the SMC modem. I had my router's IP address assigned by the DHCP on the modem, but decided to try using my public static IP and ISP's subnet mask and default gateway on the router, bypassing the modem and now everything works fine.