WordPress automatic upgrade fails - solution

If faced with a non-starter upgrade process when trying to auto-update to the latest version of WordPress (from 2.7 to 2.7.1 for instance), make sure your server can handle PHP5. Adding the following line to .htaccess file on your root (between the # BEGIN WordPress and #END WordPress lines) will ensure the upgrade succeeds.

AddType x-mapp-php5 .php