Yeah, generally when you log into a website it starts a 'session' which keeps you logged in for a set period of time determined by the web devs who coded it, most websites have long-term sessions that last for a long time, leaving you logged in for months or more if you choose that as an option. It seems the https and http sites are separate and apart from each other and thus a session started on one wouldn't be valid on the other.
I just checked the 'categories' menu and the links there are just simple '
www.bladeforums...' links without the 'https' in front of them, while every other drop-down menu at the top of the page has the 'https' at the front of the links. Makes me think the 'categories' menu was missed in the transfer of all hard-coded links over to the new 'https' setup.