Why my hook_filter not work in Drupal 6?
Given that you are only seeing 'list', I would make sure that your filter is added to an existing Input Format (check at admin/settings/filters and click on configure next to the appropriate input format) and also that all caches are cleared.  Sometimes if you start entering/coding a filter and it runs before you've got all the kinks worked out, the case 'no cache' gets in the way and stores the initial/wrong result.  Until you are sure of everything, you may want to change that to return TRUE; as well.