taxonomy access with multiple categories

I'm using the taxonomy_access module and I've a blog associated with two categories:
Cat1 : A, B, C
and
Cat2: Public, Private

I would like to restrict access to all nodes that are marked Private, but permit access to all other nodes with Cat1 ... I've set up the access grid giving permission to anonymous user to access Cat1, and to Public of Cat2
and I gave access to authenticated user to Cat1 and to Private of Cat2.

However this schema doesn't work an anon users are able to access Private content.

The taxonomy_access module README says that with multiple categories you compute the accessibility
with an OR ... Here it doesn't seems the case as a node that is Private should not be accessible to the anon user...

How can I make it work ?