The fact that there is any difference between the "top" login button and the box on the left is a hole we will soon plug.
If you are unable to login using the box on the left, this indicates that your profile is not yet confirmed. Please reply to this "sticky" post so that I can help you get through the rest of the process.
The email based confirmation process is part of our "troll" protection. While not "troll" proof, it does "raise the ante" slightly by requiring a valid, unique, email address for each profile. Thus, if we ban a profile, it will not be so easy as on the old system to simply post as someone else.