If you are running Windows 8 Consumer Preview or Windows Server 8 something like a Lenovo T410/T420 with an NVidia graphics card you may have come across this issue and an Error 1000 in the Application section of the Event Log.
I think I first encountered this when remoting in to both Windows 8 and Windows Server 8. But it was only when I opened a PDF in the Windows Metro PDF viewer that I saw the screen flickering black, and got kicked off to the logon screen.
Here are a few helpful links on the subject:
The simple workaround (via the last link):