Index: bp-core/admin/bp-core-update.php
===================================================================
--- bp-core/admin/bp-core-update.php	(revision 3959)
+++ bp-core/admin/bp-core-update.php	(working copy)
@@ -1280,9 +1280,9 @@
   		return; 
   	
   	if ( defined( 'BP_IS_UPGRADE' ) && BP_IS_UPGRADE ) 
-  		$msg = sprintf( __( 'BuddyPress has been updated! Please run the <a href="%s">upgrade wizard</a>.', 'buddypress' ), admin_url( 'admin.php?page=bp-wizard' ) ); 
+  		$msg = sprintf( __( 'BuddyPress has been updated! Please run the <a href="%s">upgrade wizard</a>.', 'buddypress' ), ( is_multisite() ? network_admin_url( 'admin.php?page=bp-wizard' ) : admin_url( 'admin.php?page=bp-wizard' ) ) ); 
   	else if ( defined( 'BP_IS_INSTALL' ) && BP_IS_INSTALL ) 
-  		$msg = sprintf( __( 'BuddyPress has been installed! Please run the <a href="%s">upgrade wizard</a>.', 'buddypress' ), admin_url( 'admin.php?page=bp-wizard' ) ); 
+  		$msg = sprintf( __( 'BuddyPress has been installed! Please run the <a href="%s">upgrade wizard</a>.', 'buddypress' ), ( is_multisite() ? network_admin_url( 'admin.php?page=bp-wizard' ) : admin_url( 'admin.php?page=bp-wizard' ) ) ); 
                   
   	echo "<div class='update-nag'>$msg</div>"; 
 }