I have a BenQ 7700 (My third one!) and I'm having a problem with what I think is light spill on the left hand side of the screen. I also see a long diagonal thin lighter tint of light (only on blacks) going through the bottom left hand corner of the screen and even going further onto my wall! The first two had random lighter blobs in the middle of the screen on dark scenes and now THIS! Maybe this is something I have introduced like a scratch on the lens, but HOW could I have done this? I'm too scared to even go near the lens!