Threads no longer being marked read
 

This just started happening within the last couple days, and I cannot think of anything that changed on the server/vBulletin setup.

Threads show up in new posts, click on go to first unread post, and it will bring you to a new post, which in some cases is the last page/last post. Click new posts again, and that thread is still showing bolded with the "go to first" unread post icon.

At the same time, another thing that happened is that you could go into a thread, post, and then go to New Posts or User CP and the thread you just posted in would show up as unread.

I first got the complaint from several members of the forum, and then realized it was happening to me as well.

I am using cookie based thread reading, because the members prefer that, because it leaves the 'read'/non-bolded threads in their User CP for a little while, as they sometimes quickly scan through threads and then go back and post. When I switched to DB tracking a year or so ago, I got complaints.

Any idea why all of a sudden the cookie based method would stop working? I do have mods, but I haven't added or changed any from the time it was working until now.