The server encountered an internal error... почему???

Хост выдает " memory_limit 32M " и не обновляет прайс, хочу увеличиь память до 64M. после добавления в " public_html " .htaccess со строкой php_value memory_limit 64M в нем, сайт перестает работать и пишет такое:The server encountered an internal error or misconfiguration and was unable to complete your request.Please contact the server administrator, [email protected] and inform them of the time the error occurred, and anything you might have done that may have caused the error.More information about this error may be available in the server error log.Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.помогите разобратся почему так.это все на joomla 1.5.8