BuddyPress.org

/wp-content/plugins/buddypress/bp-core/bp-core-signup.php

line # 237, change from the old line to the new line.

old line:

<input id="signupuser" type="radio" name="signup_for" value="user" <?php echo $signup['user'] ?> />

new line:

<input id="signupuser" type="radio" checked name="signup_for" value="user" <?php echo $signup['user'] ?> />