"I can't get in.. With IE I get a strange Active X error. With Opera I see an empty (gray) game screen and a Swing error dialog with an OK button and no message. "
It sounds like you do not have the Java Plug-in installed. Go to our home page and click the "Getting Started" link. There you will find a link to Sun's plugin download.
If, on the other hand, you are running MacOS X we still have some technical difficulties to fix. We are working on it.