wordpress - widgetized side bar id

Hi, there's occuring me something realy strange. The code gives my list categories an id like: categories-122434532 (a random number).

http://www.zaviola.co.cc/wp

but he doesn't do this for the same widget: page and other widget archives. Something wrong in the code?

<div id="sidebar">
<ul>
<?php 
			/* Widgetized sidebar, if you have the plugin installed. */

			if ( !function_exists('dynamic_sidebar') || !dynamic_sidebar(1) | !dynamic_sidebar(2) ) : //Start functie
    
					wp_list_pages('title_li=' . __('Pages:')); 

   					wp_list_categories('title_li=' . __('Categories:')); 
	 
echo  ("<li class=\"archives\">");
       				 _e('Archives:');
echo   ("<ul>");
         			wp_get_archives('type=monthly'); 
echo  ("</ul>");
echo  ("</li>");
     			    wp_list_bookmarks('title_after=&title_before='); 
echo  ("<li>");
       			    _e('Meta'); 
echo  ("<ul>");
        			wp_register(); 
echo  ("<li>");
            		wp_loginout(); 
echo  ("</li>");
            		wp_meta(); 
echo  ("</ul>");
echo  ("</li>");

			endif;  //Eind funtie
      
?></ul></div>

Code (markup):

if you can help me, I would be pleased