[Mediawiki-l] img_auth.php - Access Denied

[Holger D.]

Dear list-membersl,

  I searched the archive, found similar questions but no answers. I
  am using img_auth.php like mentioned here:
  http://www.mediawiki.org/wiki/Manual:Image_Authorisation#Another_Scenario.2C_Security_Motivated

  Unfortunately I can upload pictures but I can't access them, I only
  get "Access Denied You need to log in to access files on this
  server."
  I tried different settings in localsettings, checked rights on the
  relevant folders, was searching the internet. I have no idea where
  to search.

  I would very much appreciate some hints!

This are my Versions:
MediaWiki       1.13.0
PHP                 5.2.6 (cgi)
MySQL             5.0.51a-log

Thanks and best regards,
 Holger