How do I jump to a specific place on a page?
The problem is that you have the #, called fragment, in the path, Drupal escapes it for you, and what you need to do is tell Drupal specifically that you want a fragment in the url.

Example:

l('linktext', 'node/1', array('fragment' =&gt; 'placetojumpto'));


Documentation here: http://api.drupal.org/api/drupal/includes--common.inc/function/l/7