I just spent 6 hours trying to figure out why the access permissions would not work in an upgraded Joomla 2.5 site. In order to save you the heartburn and lost time this issue caused me, I am going to explain the problem and the simple fix (the fix is always simple if you know it).I recently upgraded a Joomla 1.5 site to Joomla 2.5. I’ve performed the 2.5 upgrade at least a dozen times and thought I knew the gotchas. But I found a new one: Joomla access permissions did not work on the upgraded site.
For example, in Joomla, if you assign an access permission of Registered to an article, then only logged in registered users can see that article. On my upgraded site, if I assigned an access of Registered to an article, any public user could see the article.
The reason pubic users could see an article with an access of Registered is because the global article option for Show Unauthorised Links was set to Yes. By setting Show Unauthorised Links to No, I fixed the problem and only logged in registered users could see articles with an access of Registered.
To set the Show Unauthorised Links option, from the Joomla Admin menu, select Content > Article Manager and click the Options button. Under the Articles tab, set Show Unauthorised Links to No.