Seems to happen when a developer logs on for the first time (to do this he/she has to get a password, then log in as a developer). This has happened twice in my experience. It accepts "Additional Comments" but not a change of status. However, when *I* changed status it was sucessful!!!
This is a "feature". "Collaborators" do not have as many priviledges as "developers". We are looking to see if this is what we really want or allowing assignees full priviledges.
This turned out to be a distinction between "coordinator" and "collaborator". My recommended procedure is to give coordinator status to those who need it. This can be done by updating/inserting into the "entities" table.