Invalid controller specified (robots.txt)

#0 /home/russianchina/www/library/Zend/Controller/Front.php(946): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http))
#1 /home/russianchina/www/library/Zend/Application/Bootstrap/Bootstrap.php(77): Zend_Controller_Front->dispatch()
#2 /home/russianchina/www/library/Zend/Application.php(358): Zend_Application_Bootstrap_Bootstrap->run()
#3 /home/russianchina/www/public/index.php(36): Zend_Application->run()
#4 {main}