Occasionally in Revit 8.1, I've experienced graphics performance issues. When I select another view from the project browser, the screen doesn't actually change, though the view name at the top of the screen has changed. And when I change applications then go back to Revit, the previous image is where the Revit plan should be, etc.
Wouldn't worry me too much, except when I go to save, I get the error message: failed to open document. I can't save locally, I can't save to central....what am I missing (besides an upgrade to 9.0)?