Check if this problem exists in fullscreen mode and compare with all the different media players you have. I think this depends of the size of the window. The borders go away when the window is sized properly. Check it in fullscreen mode also.
Check if this problem exists in fullscreen mode and compare with all the different media players you have. I think this depends of the size of the window. The borders go away when the window is sized properly. Check it in fullscreen mode also.