Index: wp-admin/user-new.php
===================================================================
--- wp-admin/user-new.php	(revision 18519)
+++ wp-admin/user-new.php	(working copy)
@@ -26,7 +26,7 @@
 this email. This invitation will expire in a few days.
 
 Please click the following link to activate your user account:
-%%s' ), get_bloginfo('name'), site_url(), esc_html( $_REQUEST[ 'role' ] ) );
+%%s' ), get_bloginfo('name'), home_url(), esc_html( $_REQUEST[ 'role' ] ) );
 	}
 	add_filter( 'wpmu_signup_user_notification_email', 'admin_created_user_email' );
 
@@ -73,7 +73,7 @@
 			$newuser_key = substr( md5( $user_id ), 0, 5 );
 			add_option( 'new_user_' . $newuser_key, array( 'user_id' => $user_id, 'email' => $user_details->user_email, 'role' => $_REQUEST[ 'role' ] ) );
 			$message = __("Hi,\n\nYou have been invited to join '%s' at\n%s with the role of %s.\nPlease click the following link to confirm the invite:\n%s\n");
-			wp_mail( $new_user_email, sprintf( __( '[%s] Joining confirmation' ), get_option( 'blogname' ) ),  sprintf($message, get_option('blogname'), site_url(), $_REQUEST[ 'role' ], site_url("/newbloguser/$newuser_key/")));
+			wp_mail( $new_user_email, sprintf( __( '[%s] Joining confirmation' ), get_option( 'blogname' ) ),  sprintf($message, get_option('blogname'), home_url(), $_REQUEST[ 'role' ], home_url("/newbloguser/$newuser_key/")));
 			$redirect = add_query_arg( array('update' => 'add'), 'user-new.php' );
 		}
 	}
Index: wp-includes/ms-functions.php
===================================================================
--- wp-includes/ms-functions.php	(revision 18519)
+++ wp-includes/ms-functions.php	(working copy)
@@ -1826,9 +1826,9 @@
 		delete_option( 'new_user_' . $key );
 
 	if ( empty( $details ) || is_wp_error( add_existing_user_to_blog( $details ) ) )
-		wp_die( sprintf(__('An error occurred adding you to this site. Back to the <a href="%s">homepage</a>.'), site_url() ) );
+		wp_die( sprintf(__('An error occurred adding you to this site. Back to the <a href="%s">homepage</a>.'), home_url() ) );
 
-	wp_die( sprintf(__('You have been added to this site. Please visit the <a href="%s">homepage</a> or <a href="%s">log in</a> using your username and password.'), site_url(), admin_url() ), __('Success') );
+	wp_die( sprintf(__('You have been added to this site. Please visit the <a href="%s">homepage</a> or <a href="%s">log in</a> using your username and password.'), home_url(), admin_url() ), __('Success') );
 }
 
 /**