[Plugin: Welcome Pack] php error sprintf()

i use wp 3.2.1 and bp 1.5.1. i get this error after registration and no email is sent

Warning: sprintf() [function.sprintf]: Too few arguments in /home/www/cwcity/hosting/5/g/5gta/htdocs/wp-content/plugins/welcome-pack/welcome-pack.php on line 753

http://ww.wp.xz.cn/extend/plugins/welcome-pack/