Can someone help an Opera newb?

[Yhor]

I'm sure it's a setting I messed up, but I don't remember the term or keyword to search and find my problem.

My problem: I visit a discussion board (like this one) and view pages. The icon that indicates that I've read the page doesn't update, but remains as a "New post" icon. I enable cookies for sites visited in preferences, what am I missing?

Thanks in advance,
~Yhor

Info-
Opera Version: 10.01
Build: 1844
Platform: Win32
System: Windows XP
Java: Sun Java Runtime Environment version 1.6

Edit: As an aside, if I reply to any thread, or create a thread, the icons update properly afterward.