This morning I updated all the user group permissions to be more inline with the proper XenForo way of doing it. This is to resolve a few minor issues left over from the migration from vBulletin.
The details aren't important but I want to make sure that I didn't make any mistakes - so if you suddenly can no longer access any forums / threads, or you can access things you previously couldn't, please let me know in here.
One issue I'm aware of is that the 'Newbie' tab is visible to everyone on the homepage, although clicking it doesn't show any threads. I'll sort this out soon so just ignore it if you don't have access to the Newbies.
Edit: If you are having problems viewing the threads on the homepage, log out and back in again.