Catchable fatal error in WP 3.1 RC3 – echo get_category_link

I have in index.php the line 6:
<a href="<?php echo get_category_link(get_theme_mod('featured')); ?>"><?php echo cat_id_to_name(get_theme_mod('featured')); ?></a>

In Wordpres 3.0.4 works perfect, but in WordPress 3.1 RC3:
Catchable fatal error: Object of class WP_Error could not be converted to string in C:\wamp\www\wordpress\wp-content\themes\cvasi-magazine\index.php on line 6