When deployed to websphere (or maybe to other app servers as well), calling any page will result with a blank page.
This happens because websphere sets the display name (aka context name) for the portal from the war name. Usually (on Tomcat), display name is null. On websphere, every application in cell must have a unique context name.
The root of the problem is in ThemeHelper, where servletContextName is being appended every time.