lately the forum tends to mark random topics as read/unread
sometimes i didnt open 20 threads in a section, load another page and when i look into this section again, all topics are marked as read
some minutes ago a thread i opened months ago was marked as not read
its no big deal, but does this problem occur for other users?

cookies based. Based on your browser and cookies, if you toss your cookies, its like you just logged in.

I don't know if it's cookie related. I know that I haven't "tossed my cookies" and yet I have had both of these things occur.

Regardless, I can see how cookies can cause a post that has been read to appear not read, but you'd have to edit the cookies, not toss them to make something appear as read if in fact it has not been read.