(at least) TinyMCE doesn't work with (at least) relax theme

My website uses the relax theme, which is a Drupal 5 theme. After installing WYSIWYG API, I noticed that nothing happened, though the javascript for the wysiwyg module plus tinymce editor were being sent to the browser.

After changing my theme from relax to garland, the editor started rendering. I am not sure if this is a bug in the module, and that's why I marked it as "support request", but I would like to know what are the requirements for it (the module) to work regarding the theme, so I can modify it to work as intended.

Thanks for the module, anyway.