When I performed an upgrade to WordPress 3.2.1 the upgrade went fine, but when trying to Login to the site it prompted for a Database Upgrade. After executing this, it would result in a blank screen with just the WordPress logo and nothing else.
To fix the problem I had to temporarily remove the file object-cache.php from the wp-content directory and restart the web application. Once I did this the database upgrade worked fine.
It appears the database upgrade process doesn’t like Wincache 1.1, however upgrading Wincache to 1.2.614.0 may possibly fix the problem. Download location: http://sourceforge.net/projects/wincache/files/development/