I've tried it with a new database and it works as you describe. However, no matter what I do with my existing database the quick search will not find any items where one of the keywords is in the item title and the other is in the item text.
Is there some setting that would cause this? Or is it perhaps related to
http://www.kinook.com/Forum/showthread.php?t=4944? I've tried the repair options suggested there but that makes not difference to this problem.