Steps to recreate:
[LIST=1]
[*]File->New
[*]Quest->Graphics->Combos
[*]RClick a combo in the combo page
[*]Click 'Locations' in the context menu
[*]Observe "Combo Locations" msgbox says:
[/LIST]
No other screens use this combo.
This kind of sounds like it is trying to say that the combo does appear on this screen, but nowhere else. But, as the steps above show, no combo was ever placed on the screen. Simple fix would be to remove the word "other."