WebSphere 7 JSP Java Version Quirk

A couple weeks ago I was working with a client to deploy some web application enhancements to their WebSphere 7 Express server and ran into an unexpected issue.  I had been developing and testing on WebSphere 7 Developer edition which is a full version of WebSphere, but with unlimited use for development.  After numerous deploys and no changes to the default configuration of the server instance I had expected a smooth deployment to WebSphere 7 Express on the client's server.  However, as it turns out the WebSphere 7 Express version defaults to version 13 of Java which is Java 1.3 even though the rest of the server is running on Java 1.6.  In order to change the version of Java for JSP compilation one must choose the detailed deploy and pre-compile JSP option to set the version to a later version otherwise any JSP's developed using features specific to versions above 1.3 will fail to compile and users will see error messages upon page load attempts.  This is just another of many WebSphere 7 quirks I've run into ever since my first experience with WebSphere on version 5.