I have a problem and I have no clue how to fix it. When I attach my macbook to a projector a picture shows up on the projection screen that is no longer on my computer (I think). I've searched for all images on my computer and the picture does not show up. This picture was once my wallpaper but since has been deleted from my hard drive. But, as soon as I attach my adapter the picture appears on the projection screen, almost like a screensaver, while on my monitor I see nothing but my regular desktop. Once I start a slideshow with powerpoint, the picture disappears from the projector and my slideshow is normal. However, as soon as I end my slideshow, the picture is projected again. Again, this picture is not my wallpaper and does not appear when I search all images on my hard drive. Any help would be extremely appreciated!