So I have a case where I have an artist in the database that is currently 2 different people
(this one: http://musicbrainz.org/artist/e47a42d7-1762-461c-bcfb-d3ae21fe1923 )
so i created a new artist with the same name (here: http://musicbrainz.org/artist/0c8551aa-cf6b-4036-adb4-3b10fe3f3556 )

Then I went to the artist where I wanted to switch the credit from the one artist to the other.

After hitting submit, it takes me to a new edit screen where all artist relationships are deleted (not just the one I'm trying to change)

Also all external links are deleted too.

Note: I took off all scripts and tried this and changed browsers and tried this and still the same result