2001-01-31 :
	* When saving without any file opened, crash!
	* MPEG input codec can't calculate number of frames for all 
	  video files, only which are encodec with good tools like
	  ucbmpeg or ganso's mpeg output codec (based on ucb ;)

2000-08-02 :
	* When user leaves the duration widget at the constant view window,
it sends us a signal. If the user leaves it closing the window, sigsegv!
