Super/subscript cannot be individually activated in Full CKEditor 4

While I can get super/subscript to show with the default Full (ie no toolbar or toobarGroups settings) configuration, as soon as I try and limit items shown, I cannot get super or subscript to show. This seems to be a problem on other implentations too e.g http://latex.codecogs.com/integration/ckeditor_v4/samples/plugins/toolbar/toolbar.html (see bottom two examples with 'Subscript','Superscript' specified but not showing on bars - underline's also missing).

Any help gratefully received

My code is:

config.toolbar = [
                 ...
		{ name: 'basicstyles', items: [ 'Bold','Italic','Underline','Strike','Subscript','Superscript','-','RemoveFormat' ] },
                ...
                ];