Michael, many thanks for your clarifications and for you patience with a joomla newcomer! Once I understood that my Joomla 1.6.3 installation for some reason was missing the load module plugin (which comes with Joomla), then I was able to install this through php and now your syntax works just fine! Indeed not a problem with your module!
Many thanks again for your help and patience!
Martin
P.S. What do you think about my improvement suggestion (in your forum, suggestion to Easy Folder Listing)?