no such file or directory in drupal multisite setup

I was getting the following error in a multisite setup

require_once(sites/[site_name]/modules/ipAuthenticator/../../../../modules/user/user.pages.inc): failed to open stream: No such file or directory in /var/www/drupal-6.24/includes/menu.inc

this seems related to #823836: Fatal error: Cannot redeclare user_autocomplete()

patch attached