I thought maybe it was an issue with me being on an older version of Serendipity, so I upgraded to 1.1.2, but it is still happening.Your search-query must be longer than 3 characters. You can try to append * to shorter words, like: s9y* to trick the search into using shorter words.
The blog is at: http://eclectic-world.com/myaddictions/animania/ and the search term was "Passion"
thanks