It appears for some reason the link submit component does not work correctly if the only thing it contains is a Bootstrap glyphicon.
For example: <t:linkSubmit event="changeCart" mode="UNCONDITIONAL">Change</t:linkSubmit> calls the changeCart event handler <t:linkSubmit event="changeCart" mode="UNCONDITIONAL"><span class="glyphicon glyphicon-edit"/></t:linkSubmit> does not
