cant activate this plugin

Fatal error: Cannot redeclare wpuf_buffer_start() (previously declared in /public_html/nyonyakost/wp-content/plugins/wp-user-frontend/wpuf-functions.php:11) in /public_html/nyonyakost/wp-content/plugins/wp-user-frontend-reloaded/wpuf-functions.php on line 12

can you help me with this?

regards,
BRAM

http://wordpress.org/plugins/wp-user-frontend-reloaded/