maria, what you're talking about is "new post indicators." they're updated when you visit the site (though it doesn't always work... sometimes you have to update them manually by going to "my profile" and clicking "update new post indicators").
the problem is that the server time changed. so, when you visited the site before the time changed, the boards noted that you were last there at whatever time it thought it was. then, the boards time was changed back 18 hours. so, it thinks you've been there more recently than you actually have. it should start working properly tomorrow. in the meantime, just look through all the posts in the forum and see what looks familiar. also, since you comment so consistently, you can check the comments thread.
one other possibility is that your browser should change the color of the links you've visited. so, look at the links rather than the indicator next to them.
hope this helps.
Paul
