API Bug: UpdateMapHighlight returns no data

The following API issue has, as far as I can tell, been introduced in 4.0:

The UpdateMapHighlight method does not return any data for the following map highlights on the Continent maps:

- Darnassus
- Orgrimmar
- Ruins of Gilneas
- Stormwind City
- Dalaran
- Deepholm
- Kezan
- The Lost Isles
- The Maelstrom

For all other map highlights, UpdateMapHighlight works OK.

Thanks for looking into this, would really help solving some issues in an add-on library :-)