Why do I see buttons in the column headers when some queries are performed and not others?
Those are "sort" buttons no? i.e. toggle id_person ASC to id_person DESC
Can the results where they don't appear be sorted?
Yes, if I hover over them, they say "sort" but don't appear to do anything when clicked. I thought I may have inadvertently enable some option to show them, but pasting another query into the sql edit window and excecuting it brings up a report without the heading buttons, so it must be something about the query that is causing it.