Re: User's cant view ANY article
Did you set the permissions for the registered user to see the articles?
I am using tikiwiki 3.0 beta1 and this is where I found the permissions for the group:
got to admin/users, at the top is a tab for admin groups, it lists all groups and one of the columns looks like a key. click on that and set the permissions for that group.
I am not sure if that's the same place for tikiwiki2.1, but if you can admin the groups, there should be a way to get to the group permissions.