UVW Unwrap and texture maps

I did not kow that the UVW Unwrap Modifier retains the images it uses in its editor as maps that are used in the scene, even when you've assigned a different material to the object. So again, any map that was used in the UVW Unwrap editor stills shows up in the Materials Editor as being used in the scene, even when its Material has been removed. You have to collapse the object to get rid of the map in the scene. Something new everyday...