comment email/author form not showing after upgrade

Hey.

I did the upgrade yesterday and everything went great, until I noticed that the author/email/URI form is not showing in the comments. For an example, check here:

http://arbol.milnombres.net/wp/index.php?p=1315#comments

The comment form appears, and it says: “Logged in as .”, as if the commenter is logged in but its not. When the comment appears, it refers to the commenter as “anonymous”. Anyone has an idea of what’s happening?