I have this issues with my Server 2008 Standard DC,
It seems like this only happens when working on an Terminal Sessions, the explorer would suddenly stop responding and if you kill the session end reopen it it will just hang and not open the session. If you log on to a different user with admin rights you are able to work on this session but when you try to restart of log off you get the following message “please wait for the system Event Notification service ! “. Eventually you have to reset the server.
Funny thing is that the server is still up and you can browse the shared folders and log on to the domain with client computers,