I am scanning slides and tried this function i PS CS. On the first pictures it worked great but now there is always a dark edge left on the top of the image.

Is there some way to tweak this tool? Most of all I am extremely annoyed that it keeps giving me a duplicate of the image when I only have picture I am using the tool on.

Ive heard some solutions where you put a different "background" in your scanner, but this solution obviously cant be applied here since I am using a slide scanner.

Any ideas why it has stopped working? I am scanning the same kind of photos as before...