Threads not displaying right?

[Tallica]

Don't know if this is happening to anyone else but on some threads when i click the little green dot it takes me to the last unread post and if I scroll to the end of the thread and click back to that fourm (by choosing the fourm not pressing back on my browser) the post shows as not bold any more denoting no unread posts. That's the way it is supposed to work.

But on most of the threads lately it is not working like this as I've read the entire post but when I go back (by choosing the fourm not pressing back on my browser) It still shows as unread!

Any help is greatly appreciated!