Recently I've started hitting the error below when trying to connect to one of my Windows 2003 Server machines with the /console option:

(Error connecting to existing session for dancre (Id 0). The operation completed successfully.)

You've got to love an error explanation of "The operation completed successfully". Restarting the server box fixes it for a while, but then it starts happening again.

Has anyone else seen this? Any idea how to fix it?