I tried three times to post a message to this user on their user wall; each time it didn't post. I posted a message on another user's wall in the same wiki without any problem.
I also noticed that when I go to this user's page, it says I'm logged out. I refreshed, and it still said I was logged out. I went to other pages, refreshed, and it said I was logged in.
http://sexuality.wikia.com/wiki/Message_Wall:Rosquilla_de_Amazonita