Impact of Upgrading Web Server to Java ES 5 Update 1 on Portal Server

On a Java ES 5 setup that has Portal Server on Web Server, upgrading Web Server to Java ES 5 Update 1 level renders Portal Server as unusable. Release 5U1 Web Server uses JSF 1.2. But JSF-Portlet bridge in Release 5 Portal Server does not support JSF 1.2. So Portal Server will not work. Do not upgrade Web Server to Release 5 Update 1 in case you want to continue using Release 5 Portal Server.