oh, i didn't even see this thread, i was thinking it was something to do with the scaling options, if you set it to aspect then it will give you black lines if not at the right aspect ratio, i like the black lines as it doesn't degrade the picture quality whereas fullscreen "stretches" the image and blurs it slightly, giving it that 80's american TV look about it, glad you've got it sorted though mate, this information will help others with the same issue.
MrNeeds