Threads That are Read Appearing as Not Read

I am having issues lately. I read a thread, but when I go back to the forum or the User CP, the thread is still in bold indicating it is not read. It doesn't matter how many times I click on the thread, it still shows as not read.

I have tried deleting my TUG related cookies and that seems to fix the issue for a week or two before it comes back. Any ideas?

I always thought this was a session indicator (doug can correct me)...ie you have to have logged off and logged back in before the read icons reset?

I never log out of the BBS, I use the Remember Me function. In the past I have not had issues. It didn't require logging out and logging back in. When I read a thread, it would unbold the thread. If a new post was made in the thread it would be bold again. This stopped working a few weeks ago and only clearing all the TUG cookies fixes it, temporarily. I can use the Quick Links/Mark Forums Read to make is so the threads are no longer bold, but as soon as a new post is made to one, reading it does not mark it as read again.