roller 3.1, user registration page exception

[Jeffrey Blattman]

fresh roller 3.1 install. when i access the user registration page, i 
get an empty page and an exception in the logs ...

javax.servlet.jsp.JspException: ServletException in 
'/WEB-INF/jsps/core/UserNew.jsp': Cannot retrieve definition for form 
bean userFormEx on action /roller-ui/user
       at 
org.apache.struts.taglib.tiles.InsertTag$InsertHandler.doEndTag(InsertTag.java:921)

any ideas?

thanks