Fatal error: Call to undefined function

This happens in Simplenews, but only when Simplenews_Template is installed. I just upgraded to Drupal 6. When I send a test newsletter, I get this
Fatal error: Call to undefined function simplenews_mail_tokens() in /home/klimatos/public_html/sites/all/modules/simplenews_template/simplenews_template.module on line 117

I am shy to switch to the dev-version, rather have your comment first.

Thanks

Theo Richel