Forum login not carried over to library section?

[#1]

I was reading a forum thread - while logged in - and I clicked on a link to a library article. I wanted to add a comment but I saw that I was not logged in there. OK, I thought - I'll log in, as maybe the login just doesn't carry over from one section to another. Clicked login, got the login screen (although it appeared under the Forums tab rather than the Library tab) and logged in.
I then went back to the library article, but once I got there it still looked like I wasn't logged in. I couldn't add a comment.
Am I missing something, or is there a problem?
Graham

[#2]

I explicitly logged out of the Community area then logged back in again and all now seems well in the Library section. I was logged in there too and was able to add my comment.
Graham

[#3]

There's a chance that you may need to remove the Community based cookies following the upgrade work that we did last week.