When viewing an old version of a page (Tools -> Page History) the PDF Export (Tools -> Export to PDF) exports the newest version of the document rather than the old version which I'm currently viewing.

Even worse when using the Ad Hoc Workflows plugin (by Comalatech) and viewing the published version of the page the PDF export also seems to contain the newest (possibly unpublished!) version rather than the currently valid (published) version of the page.