The usual reason I have to use the sheetmode command is when I am inside a viewport and there is nowhere to click outside it to revert to paper space. To avoid this problem, I generally lock the viewport (under Misc in the Properties dialog box). That also means you cannot change the viewport...
Every so often DS forces you to reload the software. I always lose all my settings when that happens. I believe there is a way to get them back but I can never find the file. Does anyone know how to do this?
Simon