I have someone using a laptop running Windows XP Pro with a Verizon Wireless air card. VPN is set to use PPTP, and all antivirus and firewall software is disabled on the computer. This issue seems to be unrelated to signal strength, because all the signal strength bars can be lit, and it will not work. At the same time, only a couple of the bars can be lit, and it will work. It seems for no reason that some locations work while others do not. When it does not work, immediately after "connect" is selected, i recieve the following error. "Error 800: Unable to establish the VPN connection. The VPN server may be unreachable, or security parameters may not be configured properly for this connection." The server to which he is trying to VPN into can be successfully pinged, and i can VPN into the server from my computer, so it is not an issue with the server. Any other network connections on the computer are disabled. When the VPN does not work, its as if it does not even try to connect, i immediately recieve the Error 800 message.