[flup]

I might have found a solution for the duplicate posts thing.. I replaced the post_thread() function with the following code:

		function post_thread($title, $message, $feed)
	{
		global $vbulletin;

		$getThread = $vbulletin->db->query("SELECT threadid FROM " . TABLE_PREFIX ."thread WHERE title = '" . mysql_real_escape_string($title) . "' AND forumid = '" . mysql_real_escape_string($feed['feed_forum']) . "'");
		$ThreadNums = $vbulletin->db->num_rows($getThread);

		if($ThreadNums < 1) {
	
			$this->ItemsAdded++;
	
			$newpost['title']   = $title;
			$newpost['message'] = $message;
			$smilie             = true;
			$foruminfo          = fetch_foruminfo($feed['feed_forum']);
	
			$ThreadDM =& datamanager_init('Thread_FirstPost', $vbulletin, ERRTYPE_ARRAY, 'threadpost');
	
			$ThreadDM->set_info('forum', $foruminfo);
			$ThreadDM->set_info('thread', $newpost);
			$ThreadDM->setr('allowsmilie', $smilie);
			$ThreadDM->setr('userid', $feed['feed_user']);
			$ThreadDM->setr('title', $newpost['title']);
			$ThreadDM->setr('pagetext', $newpost['message']);
			$ThreadDM->setr('forumid', $feed['feed_forum']);
			$ThreadDM->setr('dateline', $this->get_dateline());
			$ThreadDM->set('visible', 1);
			$ThreadDM->registry->options['floodchecktime'] = 0; // Disable flood check in memory...
			$ThreadDM->pre_save();
	
			if (sizeof($ThreadDM->errors) > 0)
			{
				$ThreadDM->errors = array();
			}
	
			$ThreadDM->save();
			
		}
		
	}

Please not that it only checks on the title.. so each post with the same title will be seen as a duplicate post and not be added to the forums. I think it works for me.. I tested it on some RSS feeds which are updated since the last cronjob and it added 1/3/4 items and not all 20 items which are on the list.