The 2.71 automatic upgrade fails and crashes wp-admin with the error:
Fatal error: Call to undefined method scbOptions::get_key() in /home4/handyma5/public_html/wp-content/plugins/wp-useronline/admin.php on line 56
I had to log into cPanel on BlueHost.com and rename the plugin directory to access wp-admin.
Running WP 2.9.2