Yep, seems to happen with some people. Happens to me at work, probably something to do with the corporate firewall. I have no idea what the problem is, but it's not a real worry. When you get that error, you can still use the forum as the error appears AFTER you get logged in, although that's not obvious at the time. use the back button or your bookmarks to get back to the home page or wherever on the forum you were, then Refresh. You'll find you are already logged in.
