wpmu 2.8.1 automatic upgrade

tried automatic upgrade, get the following error. anybody else had the same problem and if so how did you resolve it? just manual install? bit hesitant to do that…

Warning: copy(/home/financeo/public_html/wp-content/upgrade/wordpress-mu-2.8.1/wordpress/wp-admin/includes/update-core.php) [function.copy]: failed to open stream: No such file or directory in /home/financeo/public_html/wp-admin/includes/class-wp-filesystem-direct.php on line 131

Could not copy files.

Installation Failed