We are currently upgrading the website to install a new forum. In the mean time it is not possible to login, so comments and the current forum are disabled at the moment!
Update: The new forum is now live. The old forum will still be accessible for archaeological purposes, but obviously will not be updatable anymore.
You can use you login info to post in it. Although for now, you can only use your e-mail to login, not your username. We're working to make sure you can use your username to login, because we think that's more convenient. Isn't it?