After upgrading a site from Drupal 5.1 to 5.2, I now get the following errors:

* warning: chmod() [function.chmod]: Operation not permitted in /var/www/drupal1/modules/backup/functions.inc.php on line 438.
* backup_database(): backup_permission_null(): Unable to chmod file 'backups/drupal-backup-20070709173917-613334601.tar.gz'

I was using the backup module regularly under 5.1 with no problems. Any Ideas?

thanks -