With guided rule editor, "pop up input panel" does not show up to modify a Date field in RHS

Issue

With guided rule editor, user can choose a Date using "pop up input panel" in LHS. However, "pop up input panel" does not show up to modify a Date field in RHS.
Without "pop up input panel", user can input invalid data to a Date field. Also validation doesn't detect the invalid input data. With following example, user entered invalid data, "2000".

    rule "test"
        dialect "mvel"
        when
            $a : Demo( date == "01-Mar-2014" )
        then
            java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("dd-MMM-yyyy");
            $a.setDate( sdf.parse("2000") );
            update( $a );
    end