The way you describe it, I believe that it doesn't work in Moodle 1.5. (There was a major change in Blocks for 1.5, to allow for future needs. Unfortunately, this meant that old blocks would not work with 1.5).
Sadly I can't help you further, because I 'm not up-to-date with several blocks that have been contributed by the community, it's all happening so fast! Maybe someone else knows more.