Multisite User Management

Im using Multisite User Management and setting up the default ROLE to contributor. But if Im using your registration link, the wordpress will keep assign the new user to subscriber and directly send the machine generated password with asking the new user to activates.
If any user register through regular registration link such site.com/wp-admin and register its working normal as I expected. Do you know how to fix and synchronize to the correct process of registration?

http://wordpress.org/extend/plugins/login-with-ajax/