search for: usageerror

I''ve got Ultrasphinx powering the search on my Rails app. It''s working with all of my models when they''re first indexed, but then, after what seems like a random amount of time, I''ll get the following error on just *one* of my models: search#show (Ultrasphinx::UsageError) "Invalid class name \"Playlist \"" I set up this model like so: http://groups.google.com/group/rubyonrails-talk/browse_thread/thread/5b48ce4d0de24493/fea38ecd29eaa68b ...and like I said, it works just fine off the bat. But eventually something goes wrong and I get the error...

...:weights => {''titre'' => 5.0, ''content'' => 2.0}, :page => params[:page] || 1, :filters => {"lang" => "fr"}) Result : UsageError : field "lang" is invalid :conditions => {"lang" => "fr"} doesnt work too. I want to filter my results (lang, country, date, etc...) and group by title. Ultrasphinx doc doesnt speak about that. Just query work ^^ And I dont really understand what are "fac...