Happy, welcome to the MacNN Forums! Please note that this is anything but an OS X issue. It's either the VPN application you're using, or something to do with the networking settings on your machine. I'm going to move this thread to Networking, because I think you'll get more information and a better chance of finding a solution there than in the Applications forum.
Keep in mind that for most people, VPNs are extreme black magic (including the need for chicken guts and specific phases of the moon to do certain configuration changes), so be prepared for a few "out there" suggestions.
Again, welcome!