My TCP/IP connection was being corrupted whenever a redial was required due to signal loss (on a 1xEVDO connection).ipconfig showed two PPP entries one with a zero IP address and a new one, unfortunately below it on the stack and so never accessed.Eventually I tracked it down to Zone Alarm's presence. I don't think Microsoft's firewall is that good but at least I don't have to reboot severasl times a day.Regards