Bookmarklets:t() and s() random behaviour depending on source websites.

i've created the following bookmarklet:

javascript:u=document.location.href;t=document.title;s=window.getSelection();
void(window.open(%22http://exemple.com?q=node/add/alerte-texte&edit[title]=%22+escape(t)+
'&edit[field_extrait][0][value]='+escape(s)+'&edit[field_url_article_source][0][url]='+escape(u),'_blank',
'width=1024,height=500,status=yes,resizable=yes,scrollbars=yes'));

It sometimes work, and sometimes not ...
On the CNN Website(www.cnn.com) or Drupal.org website, it works.

But on Le Monde web site (www.lemonde.fr), title and field_extrait don't get any date.

I am using :
Drupal 6.14
Prepopulate 6-x.1.1
non clean URL

If you are using prepopulate as a bookmarklet, can you give a try on any article from www.le monde.fr and tell me if it works?

Thanks!