Site Does Not Refresh
 

As with Popsicle (in another thread) I'm finding the same issue of the site not refreshing when an action is performed. Often when I come back to the site it tells me that X number of people are online, but after a forced refresh that number changes. Also when a forum has been read completely, the indicators still show that there are unread posts. Sometimes a forced refresh is required a few times before the site updates.

I have the supplied .htaccess file in the root directory - unmodified.