Forum subpages redirect to root sometimes

Sometimes when entering a sub-forum, or a thread, the site redirects to the forum root. My impression is that it's after I haven't used the site for a while (minimally a few hours or a day), and usually when I arrive from a search engine or when using a URL directly. Pasting the same URL a second time shows the page correctly. The problem may also affect other site areas (*.forum.nokia.com).

It happens with multiple browser flavors, and it's not new, it's been like that for at least months. I'm not fully sure of the when and how because it doesn't happen often enough, but the above is my general impression.

I guess it happens when your "login" expires. Some 7-10 days with "Remember me". Personally I log out and log in on every Monday and Friday in order to avoid this effect.

It happens also when I'm not logged in, which is the usual case.

But there's already [thread=212182]a thread on the topic[/thread] (I couldn't think of suitable search keywords to see if there's already a related thread, but noticed now there is one near the top.)