I think this is related to the "login" problems that some members have reported.
I have noticed an issue with redirects that will be causing people using the old url (whether from bookmarks, browser history or page links on the web generally) to be unauthenticated, despite having logged in and having the necessary cookies. Well, foreigner noticed it but I've been trying to work out what's going on.
There is a redirect in place so if people access "http://www.bluelight.ru" (the "old" front page url), they will be sent automatically to "http://www.bluelight.org", the new front page url.
There seems to a be a separate redirect in place so if people access non-front page material, like "http://www.bluelight.ru/vb/content/75" (the old url for the Research Portal) they are forwarded to "http://bluelight.org/vb/content/75". Notice the missing www.
After such a redirect, I am not logged in. If I try to log in, then it says Thank you for logging in, returns me to the page I was looking at, yet I am
still not logged in.
If I put the "www." in manually, then I am logged.
So it looks like these "non-front-page" redirects should be redirecting to "www.bluelight.org" and not "bluelight.org".
Alternatively whatever it is that is not letting us authenticate for "bluelight.org" could be fixed.
The same applies for non-front-page material accessed using the domain name bluelight.org.
Aby there is more chat about this in the staff forums, not sure if you're active in there, which is why I'm posting this here.
Now obviously this is not a problem for people who are accessing the site as
www.bluelight.org. I have updated my bookmarks so it's not a problem for me, but it appears you are, quite rightly,
intending to cater for people using bluelight.ru,
www.bluelight.ru and bluelight.org, and it seems that's not working smoothly.
edit: I've just noticed that the behaviour is different between Firefox and Chrome

I've been doing the testing under Chrome so I'll need to check out Firefox, maybe it's adding in the www. automatically or something.
further edit: OK I've just tested and the problem exists in firefox too. It exists for all HTML page links, and it exists for directly entered URLs too, sometimes firefox will add in the "www." automatically itself, before it even sends a request to the server, just checked with the network sniffer, it seems to be something to do with whether it's in history/bookmarks or not. So I don't think this changes anything.
Just as a "real world" example, we have sort of directory in EADD which links to a bunch of threads (nsfw'd for size, no nudity):
All these links
work, but I'm unauthenticated.
I will just do a search/replace to fix that specific post, but I'm sure there are many other links and lists of links floating about BL.