Jagged looking shapes on stage in work environment only

Hello all,
I’ve encountered a minor issue when working with Flash CS5. When I draw on the stage using any of Flash’s drawing tools (a rectangle for instance), the shapes appear very jagged and rough looking. When I preview the movie the shapes are smoothed appropriately and look very good. Is there a setting somewhere in Flash that controls work space aliasing? Has anyone else experienced this? Any help would be much appreciated.
Me