I was thinking of making an HTML version of a recently posted PPT file on the WMF vulnerability. (I've misplaced the link at the moment, sorry.) Here was what happened:

(1) Export all slides to PNG using Save As: the text appeared in the correct place, but I have no control over image size without making a registry change.
(2) Export all slides to PNG using VBA: slides that used the "title" placeholders on the slide master had the text "indented" from the correct position.
(3) Change design template: VBA worked as expected.

I simply could not find any reason that text inside a placeholder should move when using slide.export. If anyone thinks of a reason, let me know!