problems with contact form translating in admin panel ?

Warning: sprintf() [function.sprintf]: Too few arguments in ../gallery/plugins/ContactForm/classes/cf_config.class.php on line 115

Warning: Cannot modify header information - headers already sent by (output started at ..gallery/plugins/ContactForm/classes/cf_config.class.php:115) in ../librairc/gallery/include/page_header.php on line 98

when u try put new text at localization languages box, it says saved succesfuly, which is not.. coz it stays as array when u back and check the form text..