Lockouts when using Remote Desktop

Archived from groups: microsoft.public.windowsxp.work_remotely (More info?)

Hi,
We have a LAN in our store and a LAN at home. There is a Linksys router
with VPN endpoints on each LAN. We establish a VPN between the two routers
and then use Remote Desktop to operate store computers from our home (which
is 1200 miles away.) We have been doing this for two years and it has been
pretty reliable, aside from random problems. But a few weeks ago we
installed the XP-SP2 upgrades and a number of subsequent patches and now we
are having problems with one of the remote systems. It will allow us to
remotely login, we can use it for a while (not a consistent length of time)
and then it will lock us out of the remote login with the system is not
available error message. After that, we cannot get a remote desktop
connection on that system until someone up at the store restarts it. Since
we do our work after closing time, that means we must wait until the next
evening, and that is very inconvenient.
We have tried pinging the locked out system through the VPN and it
replies. So I don't think it is a VPN issue. We are also able to login to
other systems through the VPN. Unfortunately, they don't have the data that
we need on them. We can even navigate to the locked out system using
Windows Explorer and up/download data when it is in the "remote desktop
locked out" mode. We just can't log back in once we've been locked out. We
have also called and asked the people in the store if they see any Norton
Antivirus messages (I think NAV got "upgraded" at about the same time) and
they say that they do not see any.
It seems to be an issue related to the Remote Desktop or terminal server
software on the remote computer. Has anyone seen this before? Any idea
what might be wrong or where to go next in my troubleshooting?
Thank you,

--Brian M. Godfrey