[THIN] users not visible

We have a PS4.5 farm runnin gon windoes2k3.  I have a server that if you look at the users logged in for the server as whole, you can see the users logged in to that server but cannot shadow them.  If you drill down in the access console and try to look at the users on that server only they never populate.
I have done some looking around at this and it seems as though rebooting the server gives a temporary fix.  Has anyone seen this before?
Jason


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