Please notice that the Infrastructure Update KB has been updated to include the following:
Known issues discovered after release of this update
Installing the Infrastructure Update in a SharePoint farm that uses Alternate Access Mapping with a reverse proxy or a network load balancer, such as in an extranet deployment, may cause some public URLs to become unresponsive. Microsoft is aware of this issue and is developing a solution. Before installing the Infrastructure Update, customers who use this configuration should use a test environment to verify that public URLs remain accessible after the update is installed.