Toggeling https/http only when logged in as user [solved]

Using drupal 6.24, secure pages 6.x-1.9, secure pages hijack prevention 6.x-1.6
Activated: Switch back to http pages when there are no matches. Make secure only the listed pages.

When logged in as user everything is working fine.
When logged out (Drupal-Cache und Browser-Cache cleared) entering a secured page the first time http switches to https. Going back to a non secured page (i.e. Startpage) https switches back to http. Going back to the already clicked secured page again, http does not switch to https.

Clicking another secured page it's toggeling to https again. When clicking the startpage again https does not switch back to http. Toggeling only works, when clicking a secure/none secure page the first time.

After clearing the caches everything starts from the beginning again.
After logged in as user everything works fine without problems.

You may have a look at:
http://www.alpenverein-frankfurtmain.de/content/mitglieder-service = non secured page (Navigation: Angebot und Service > Mitgliederservice); sub-pages are secured-pages.

Any help or hint would be appreciated.