Nathaniel Irons wrote:

> Graham Dunn (graham dot dunn at leitch dot com) wrote on 6/23/06, 11:17 AM:
> 
>> Is there any possibility that your ISP is interfering with VPN traffic
>> inbound to your home?
> 
> Sadly, the problem's been reported by everyone who uses the VPN on a
> regular basis, and they don't all share a common ISP. I've tried it
> through Comcast and a local DSL provider.

Grasping at straws here, but try setting the MTU on your WAN interface
way down (start at 1400). Maybe the extra encapsulation of the VPN
packets is tickling some strange limit at your ISP...

from exec.php

ifconfig <WAN interface> mtu 1400

You can also force this in Windows for PPTP connections:

http://support.microsoft.com/?kbid=826159