I just detected a bug, when I discovered a section, that is new to me.
Beeing on http://project-gc.com/Profile/ProfileStats
you are able to add caches to your milestone and hidden list.
So I've tried exactly this, which unfortunately doesn't worked (first of all I've got a HTTP 500).
Tried it a second time and it is reproducible, that the lists are not saved corrently.
Please try the following.
Create a new list:
Create a second new list:
SELECT ListMilestone => EDIT (doesn't show type [milestone or hidden]]
SELECT ListHidden => EDIT (does show type [milestone or hidden]]
SELECT ListMilestone => EDIT
(Re)-SELECT radio button "Add this list to my Milestones tab"
In this case "ListHidden" get's deleted ;-)