I’ve been having this problems for years. On some of our networked computers, we use Cisco VPN over DSL. In order to have drive mapping and such, we need to enable “start-up at login”. For some reason, on a few of those computers (always the same), after a while, the VPN dialog box doesn’t appear at login, even though the box is checked. Removing the check mark, restarting, and putting it back, then restarting doesn’t help. The only fix I’ve found was to reinstall. We have SP2 on all of our computers and the Windows firewall is disabled. We use HIPS as a firewall, but I doubt that this is the problem. If it works for months, then suddenly stops, it sort of rules out firewall.
Over the years, we’ve used both Entrust (certificate authentication) and group authentication.
Any ideas?