Flag crashes while selected in the homepage, but perfectly working in the node view

Dear all,

I am facing a problem with flags.
After I've updated the theme of my website from http://avanti.co.it to http://ita.travel, the flag "Add to my itinerary" stopped working in the home page, while it is working into the node view.

After clicking the button from the homepage I am redirected to the following link http://ita.travel/avanti/ajax/category&type=promote&language=da
and the recordo is not added to the itinerary. The button doesn't even start the jquery throtteling.

While I push the button from the node view, everything works smoothly.

Any idea or suggestion about where to start watching in order to fix?

Thanks upfront for help!

Valentino.