Users at one of our sites are all the sudden getting the "you are not

logged in", and then are getting the login page. client trust is
reporting 10,000+ failures. We are in a network freeze at the moment,
and
no changes have been made to the clients, or to the servers. Why
would
this happen all of the sudden? They were able to access the proxy
server
just fine for several months, and then client trust stops
authenticating
them. The only workaround is to map a drive to the server and then
open
the browser. Is this DS related?