Wrong title of post in sidebar when viewing list of classifieds

Hi, here's the problem: look at the site http://domainmarket.sk/classified/dobryzubar-sk-dobryzubar-com-web/ - it's single classified. In sidebar you can see widgets - 2 feeds from classified categories and the last one with last forum posts (bbpress). Everything is OK but when you look at the content of taxonomy.php - archive of Classifieds category, you can see the wrong titles of widget items in sidebar. In these widgets the title of each one item in feed list is distributed by:
<?php the_title( '', '' ); ?>
But instead of this shows "Kategória: Domény na predaj" which is exactly <?php the_title(); ?> of taxonomy page http://domainmarket.sk/cf-categories/domeny-na-predaj/.
So it works everywhere else (on homepage and other pages), but no on taxonomy Classifieds archives.
How can I fix this?