Apache Solr is a great full text search solution, i have set up it for some drupal based sites of mine. Everything works ok except it could not return return unicode query correctly. I have googled this prob for Drupal and Apache Solr integration but nobody asked before.
Finally, I talked a Java guru. He tell me about problem for Tomcat/Solr. There is no error at Drupal instance. I tried to fix this by googling about Solr unicode encoding. I fugured out by following configuration.
Adding URIEncoding="UTF-8" to server.xml of Tomcat config file. It should look like:

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