not able to use anchors

I have a page with neatly buildup headings and like to use a popup to one of it's headings:
`samen:page#part2`
but that renders a the message (page) :  "page doesn't exist yet".
Of course the full url works in the browser and using anchors works in dokuwiki too...
deleting the anchor in the popup-path shows the correct page (but not at the correct position of course...)