Hi Susan. Sorry for the delay in replying but have been really busy.
The forum threads started by 'Automatic' are actually created by someone clicking on the discuss button at the bottom of each page. These are threads which are actually linked to the individual page and do not feature in the main forum index. When the discuss button is clicked on and no thread has previously been create for that page then the thread is created by the wiki, therefore 'Automatic'. This would only happen where a (0) is given next to the discuss button. Obviously whoever clicked on the button decided not to actually add a message and that way empty threads can be created by the so-called 'Automatic' and with no title either. Where the discuss button shows a number greater than (0) then there will be that many posts attached to that per-page-discussion. So it's best not to click on a (0) discuss unless you wish to leave a post relating to that particular page.
See the thread at http://lulu.wikidot.com/forum/t-4351/buttons-at-the-bottom-of-each-page for more info.
Hope this helps.