Okay, this is strange...

I'm currently using Firefox 7.0.1 with private browsing enabled, and all cookies (including 3rd party) disabled.
Yet... I'm still able to log into this forum and make the posts and stuff the usual way if I were to enable to cookies...

Thought you couldn't do that unless you stored cookies into cache... or is there some kind of hidden session cookie I'm not aware of being stored in my browser cache?
I'm not using any of the privacy add-ons I should be using ATM.