No, the only configuration option is if you want to allow weblinks to open in a new window, and it should have been set to yes.
If you copied the text file and made it the snippet code, it should work. Perhaps you tried to copy just the modifications I made to your existing snippet, and a key piece was not added. Here are the steps I took and the places I modified just in case...
1. add content to the end of the following query:
$children = $modx->getActiveChildren($listParent, $orderBy, (!$orderDesc) ? 'ASC' : 'DESC', 'id, pagetitle, description, isfolder, parent, alias, longtitle, menutitle, hidemenu, introtext, content_dispo, contentType, type, template, content');
if not the weblink content ( url to go to ) will not be present
2. added this block which checks for the type ( document or reference ) and if new windows for weblinks is set to yes
// Weblinks in new window
// 6/23/06 11:50 pm est
// check if this is a reference type document (weblink)
// set the $new_window_for_weblinks to yes if you want to allow new windows
$new_window_for_weblinks ="yes";
if($child['type']=='reference' && $new_window_for_weblinks =='yes'){
$linkurl =$child['content'];
$target =$child['longtitle'];
// weblink ahref link
$link_ahref_string ='<a href="'.$linkurl.'" title="'.$child[$titleOfLinks].'" '.$target.'>';
}else{
// standard ahref link
$link_ahref_string ='<a href="[~'.$child['id'].'~]" title="'.$child[$titleOfLinks].'">';
}
I had to change the ahref string since the weblink is not an [~id~] link any longer
3. In 3 areas of the code where the links are created, I added the $link_ahref_string variable, the original code is commented out like this:
//--->
and the new code is after the commented out original.