After debugging locally on static HTML, I found that the problem is due to the usage of the menu system of www.dnn360.net.
if you look at the site:
The DNN framework is loading jquery1.4.2 which is compatible with our module and all other jQuery librarys. However from the source code below, I found the menu is loading jquery 1.2.6 (/Portals/0/Skins/mu_sk2/CISS_MU_Horiz...)
the jQuery UI and most of the jQuery Libraries will not work in such an old version of jQuery.