There is a minor bug in the WordPress 3.1.3 Upgrade that you might run into.

The bug causes an error with your Media Library and the bug seems to only raise it’s head on WordPress sites that have one or more of these Plugins installed:

• Subscribe2
• cbnet Different Posts Per Page
• Gengo
• WP Multilingual

If your WebWorks & Design web site is using any of these plugins or you are getting an error after upgrading to WordPress 3.1.3 there is a fix. Just simply install this plugin… http://wordpress.org/extend/plugins/hotfix/