OK Guys,
I worked this out it is definitely linked to the memberships plugins being used. I found that for non members they were not seeing the first post. I then disabled the membership plugin and found that the non members could now see the first post.
I re-enabled the membership plugin (Paid Membership Pro) and looked for a setting which might be causing this behaviour. I found it in PMPro – Membership>Filter searches and archives? I set this option to “No – Non-members will see restricted post/pages in searches and archives”. and tada it is now working.
This setting’s description is a little misleading on first glance but I assure you non-members will not see restricted forums or topics.
I know other people have has similar success in their chosen membership plugin so look for that elusive setting and test it out.
Cheers
Camo