Selecting 'None' for a plugin doesn't work

When selecting 'None' for a plugin in the Premium plugin settings, the plugin is still showing up in the user's admin.

There are certain plugins I don't want to be shown in admin of other users.

EDIT:
I think there is a problem, as if I set the plugin for 'Pro', it is also showing up in the admin of a user that hasn't upgraded.

Would this be because rht eplugin was added before I set up Pro Sites?