Revit 2010 is not able to recover a lost network license when Revit is running. The program switches to Demo mode and any open data files will not be saved.
Solution (well, kind of...)
The files attached will allow Revit 2010 to recover a network license while running. If, after a 2 hour grace period, a network license is not found, Revit 2010 will display a dialog with the options to Save As & Exit or Exit. The user will not encounter Demo mode at anytime during this process.