I just got my new projector (Benq PE8700+) and had to hook it up. Well, I placed it on a tabletop at the distance that I will need and the top of the image seems to curve downward on the right hand side (top). Keystoning is straight and the bottom lines up, but then I see curvature just at the top right. Anything I can do about this? Hope I am not stuck with this on such an expensive machine. I didn't see this on the display I saw.