The directory module does a better job. At the moment it's marked as "alpha 1" for Drupal 6, but in my experience so far it works pretty well (no bugs).
Simply install it and a 'directory' item is added to the navigation menu. The configuration is simple, you select the node types to exclude from the directory, and the vocabularies to present in the directory.
The directory page lists each of the vocabularies, then within each vocabulary the terms in the vocabulary.
It appears to override the normal taxonomy term pages and add to it the child terms. Unfortunately it doesn't show the term description.