[TYPO3] strange problem with damdownloadlist... magic??? ;)

[Bartek]

Hello!
I can`t find out what is wrong with my configuration of damdownloadlist 
ext. I use standard configuration provided with this extension:
//-------------------------------
plugin.tx_damdownloadlist_pi1 {
   template = fileadmin/tmpl/tmpl_list.html

   # date Format (example)
   dateConf = d-m-Y

   # html class attribute value:
   iconCssClass = ddl_icon

   # icon for hidden records:
   iconHidden = hidden.png

   # icon base address (example)
   iconBaseAddress = EXT:dam_downloadlist/res/ico

   # all files relative to extension's res/ico/ directory,
   # or iconBaseAddress property.
   mediaTypes {

     DEFAULT {
       DEFAULT = default.png
     }

     text {
       DEFAULT = text_default.png
     }

     image {
       DEFAULT = image_default.png
     }

     application {
       DEFAULT = application_default.png
       pdf = application_pdf.png
     }

   }
}

//------------------------
And when i put files into extension`s list they apear in frontend but 
other day when i load site (anything changes) files are not shown in the 
FE I go to BE to check what`s going one and nothing is changed i save 
once again and after reloading the site... magic the files are shown 
again, I thought it was just exident but I got the same situation and 
made the same "resaves" of the extension`s config many times and 
everything then is repeated according to the above mentioned scheme.
I completly don`t know what`s going one... magic???
I would be very grateful for any help you can me provide solving this 
problem.

Thanks in advance
Regards