When switching to the 'advanced' tracklist editor while adding a release via the CD TOC lookup:

• A spinner and the text "Now loading tracklist..." is shown forever.
• Below it, the album tracklist is shown, but each track number is shown twice (and only one is correctly filled it).
  This occurs in both Firefox and Epiphany (WebKit)

I've attached a screenshot that shows the issue.
Note that the URL I am using to add the release is:
http://test.musicbrainz.org/bare/cdlookup.html?id=8lRc7wZA.0.X5ev3Mc3rj1VLbs8-&tracks=3&toc=1+3+57922+150+16931+33548