This is very weird. The search string disappears along the way. Normally you can see the search string after the q= parm in the URL but when using Chinese characters they are gone.
This does not happen when the w= parm is behind it. As I cannot read those characters and cannot conclude whether something that should be found is inputed: could you try to switch on para_weblog_always http://book.pivotx.net/page/app-a
That should take care of always putting the weblog parm (w=) in the URL.
Quality is in the detail of things............