[kh99]

I think you'd have to edit the code. in admincp/misc.php around line 1386 is this:

$deletethreads = $db->query_read("
	SELECT *
	FROM " . TABLE_PREFIX . "thread
	WHERE title = '" . $db->escape_string($thread['title']) . "' AND
		forumid = $thread[forumid] AND
		postusername = '" . $db->escape_string($thread['postusername']) . "' AND
		dateline = $thread[dateline] AND
		threadid > $thread[threadid]
");

I think if you delete the line in red it should ignore the timestamp. (Edit - You can't comment it out with // because it's in the middle of a string)