2.05+ Central Participants: How to add dropdown values?

Hi,

I am not sure if I stumbled uppon a bug, or if I just don't know how to use a feature.

We just upgraded our limesurvey installation from 1.92x to 2.05+, and we want to start using the new central Participants database.
I added an attribute to the central participants database, changed type to "drop-down list", but I am not able to add an option value. See screenshot here: i.imgur.com/BLNTJqj.png
In the Participants panel, the attribute value of the drop-down list attribute says "undefined", see here: i.imgur.com/7AqKvXC.png

I even reproduced the issue with the limesurvey online Demo using Chrome & IE10:
Demo.limesurvey.org/admin/admin.php

Is this normal behaviour? How/Where can I add option values to the drop-down list?

I am going to report this issue as a bug to bugs.limesurvey.org, as no one replied here