Ok, scuze ca nu am precizat de la inceput.

Corect ar fi:
Cod:
<div id="thumbs">
<?php 
$otherFeaturedPost = new WP_Query();
$otherFeaturedPost->query(array('showposts'=>6, 'cat'=> get_option('fslider'), 'offset' => 0, 'post__not_in' => array(get_the_ID()) )); 
?> 

<?php while ($otherFeaturedPost->have_posts()) : $otherFeaturedPost->the_post(); ?> 
</div>