Before a task can use any Graphics folio calls, it must first open the Graphics folio using:

Err OpenGraphicsFolio( void )

When executed, this call opens the Graphics folio. It returns a positive value if successful, or a negative value (an error code) if unsuccessful.

If you don't open the Graphics folio before you make graphics calls, your task will die a hideous death the first time it makes a graphics call. If your task seems to be bombing for no good reason, check to make sure you've opened the Graphics folio.