I'm trying to restrict access to a certain category, "premium," so that only WP Subscribers (and admins) have access to it. I want to keep all anonymous visitors from access to the "premium" content. Role Scoper seems like it would fit the bill but after searching the forums and documentation I still can't seem to make heads or tails of it. Any advice would really be appreciated. Thanks in advance.

After corresponding with flevato, I determined that his site was affected by the following bug, now fixed in Role Scoper 1.3.9 :

* BugFix : Category Restrictions were not applied to a post if it also had a tag in a non-hierarchical (tag-type) taxonomy