If some window (for example netscape mail) have the window border moved outside of the workspace then there is no way to move this window back because the border is not accessable. In twm 2this is easy - click on background and sevect window operation -> move. In sawfish it is really difficult.. Even if I restart the program, the window location is remembered and next time it is opened in the same position.
keep the [ALT] key pressed and 'grab' any part of the window with your mouse - you can drag the window to the desired position.