when using the create polygon too, to add additional dots in areas around an image plane, just hold left click and click drag the next point until you see where it needs to be.
i think this will solve the problem your having, if it doesn't then... lol
3D Modeler and Texture Painter (Learning)
"We have limits.... our imagination does not"
Final Year: University of Bradford (Worst place to live and study in the UK!!)