I installed pro sites with the premier plugin manager and also tested the premier plugin to see if it would work. When I select which membership level will have access to specific plugins I still go on a site (basic wordpress membership) which shouldn't have certain plugins and they still show up. I did the following....
1) installed plugins
2) created different levels of membership
3) installed premier plugin manager (first but also try the same steps with plugin manager)
4) selected which plugins would be available at which levels
5) log in as admin into another site on my network with a base level which shouldn't show certain plugins but they still show and I am able to activate.