projecter will not show viewing area using windvd 8

[hdvideoer]

my hd projector is attached to the external monitor port of my laptop. it is set to duplicate the computer monitor, and it does that exactly untl[ i try to vtew an mpeg 4 file, it plays correctly on the computer monitor and the areas surrounding the viewing area are shown correctly but the viewing area is black. any suggrstions would br appreciated. thanks