Same here.
The only reason I could even post this was because I clicked on the 'forgot password' link and was emailed a new password.
That new password lets me post on the forum but when I go to the main page and attempt to login with it, it says I still have the wrong password
From what I can gather the Forum password and the site passwords are stored separately and so the Forum is still accessible with the 'lost password' while the site is not.
KGB