thank you for your answer.
I am using the version 2.06+ and I havent updated the version since 6 months (but the ranking still worked one month ago), also the server hasnt been updated 6 months.
This problem occurs in chrome, firefox and internet explorer and I cleaned the cache of all browsers.
its supposed to work with a double click and than put the items into an order. when i double click on one item, nothing happens and i cant pull it to the other site.
unfortunatley I cant give you a link as it is a research project that hasnt been launched yet