Are you using WordPress theme Titan? Yes, the same theme that I use for this blog. Bad news, custom WordPress menu is not working with this theme. To fix that, simply open file header.php in titan folder.
Delete these lines of code
<div id="navigation"> <ul id="nav"> <li class="page_item <?php if (is_front_page()) echo( 'current_page_item');?>"><a href="<?php bloginfo( 'url'); ?>"><?php _e( 'Home', 'titan' ); ?></a></li> <?php if ($titan->hidePages() !== 'true' ): ?> <?php wp_list_pages( 'title_li=' ); ?> <?php endif; ?> <?php if ($titan->hideCategories() != 'true' ): ?> <?php wp_list_categories( 'title_li=' ); ?> <?php endif; ?> </ul> </div><!--end navigation-->
Then, add this line of code right before <!–end wrapper–>
<?php wp_nav_menu(array('container_id'=>'navigation', 'menu_id'=>'nav')); ?>
Congratulation, now your blog is compatible with WordPress custom menu.