You might need to do that screen shot but with the layout in layout mode and without "show sample data" enabled. Then no sensitive data is shown. (You can also edit a screen shot by "Scribbling over" sensitive data in the shot to obscure sensitive items form the screen shot.
Is the "Delineate...." check box selected in layout setup? If you clear it, does it make a difference. (This is a long shot, but a quick fix if its the culprit.)
Delineate was ticked but hasn't made a difference to untick it. I'll have a look at getting some sort of screen shot...somehow :)
Just as an update, I've discovered that adding a blank trailing grand summary to the base of the report actually solves this problem :)