[SOLVED] - Translation tool - words missing

[Kicsihun]

Hello Everybody!
I have developed a Layered Navigation module, but some of the words I need to translate for it, won't show up at the Translation tool.
The words from the module's __construct function and .tpl file are visible, but the other words I'm using in the module's functions aren't listed.
e.g.:

function getFilteredCategory($filters)
   {
       /*some code*/
       $return = $this->l("Category");
       return $return;
   }

In this case the "Category" word isn't showing up at the Translation tool.
What might be the problem?

Thanks!

[Kicsihun]

Can someone please help me?