- problem with google maps (specify API key)
- some issues might be caused by yandex script you have placed to your body (not sure)
But definitely there is 1 issue with theme.
In item-post.php find this line:
$def_cat['fk_i_category_id'] = Params::getParam('sCategory');
Right bellow this line place following code:
$def_cat['fk_i_category_id'] = ($def_cat['fk_i_category_id'] <> '' ? $def_cat['fk_i_category_id'] : 0);