Recursive frames on beta website [5.0.3-B2]

Imported From: http://groups.google.com/group/in-portal-bugs/browse_thread/thread/91a8bcb7a2e1213b#

Got frame in frame - mirror effect, when clicking on folder, like "Configuration".

Happens, because of js error:

getFrame("head").$ is not a function 
getFrame('head').$('#extra_toolbar').html(''); 

Tested here: http://beta.in-portal.org/5.0.3-beta2/full/admin/index.php?env=-index:m0--1--s-

Doesn't happen on my installation. Maybe "head" frame was modified locally in a bad way?