I now see what you're saying Friedrich, I must add my Sample Data Feature to those Setup Types in order for it to be 'selected' as such.

On another note, I want a dialog with 2 checkboxes sometimes and a 3 checkboxes at other times, but the first 2 checkboxes are the same. Is the only way around this to have 2 dialogs??? Which is what I've done, hiding and showing each in turn, but just checking there isn't an easier way.