Facebook Connect

Hi!! Hope everything is going well!... well, Im using this plugin (ultimate facebook) and it works very nice but when I use it on a mobile device: it opens FACEBOOK to make the user enter his credentials but when clicking login on facebook it should close facebook's page and return to my site as a logged in user. But it only displays: page not found on facebook, so it is not closing anything and is not comming back to my site. (happen whith my Ipod, Iphone, Ipad and blackberry... not tested in others... but I need this to work in those devices) PLEASE HELP!!