It used to be that when I opened a thread, then went back to the main forum page with all the topics, the topics I'd read would be in purple and the unread ones would be in blue. Now they all stay blue and it's hard to keep up with what I've read and what I've not. I've looked for a setting that might have been changed and can't find one. I am using Mozilla Firefox now. Does that have anything to do with it?