Hello, I am a teacher and I've been using my Macbook at school and connecting it to a projector for quite a while with no problems until today. Today I plugged in my projector cord and the image on the projector screen was very dark and the picture was not sharp at all. However, on my Mac screen everything looks good. I have not tried hooking up my PC to the projector yet to see if it is a projector problem or not. I plan on doing that later. However, what leads me to believe my Mac is at fault is a couple of quirky things my display settings have been up to the past couple of days. I accidentally set a picture as my background image- and set it back, no problem. But, it keeps switching back to the unwanted image at weird times! Sometimes it happens when I turn it off and on, and other times it could happen when I exit and re-enter DVD player. I'm thinking whatever problem caused this may be linked to the projector image issue as well. I'm thoroughly confused. Please help.