Membership plugin - cookie issue?

Following up on my earlier post about use of the membership plugin on http://www.socialmediashop.co.uk ...

Seems like sometimes it works, sometimes it doesn't. I've noticed that when I'm logged in as Anco (password: clavier6 for testing purposes) I can see the right pages now (level 1 - go to Members in the nav bar to log in and access each level) but when I log out I can still see the level 1 pages, even theoretically they should divert to the No Access page for a stranger (free user). Not sure if this is what's causing it to seem like it's working intermittently.

Really struggling and have the client at my neck :wink: