1. Well, that would be a solution (although it is semantically different from what I really want)

2. The corresponding code:

<a:region>
 <a:outputPanel id="<% !a_id %>">
 <a:repeat var="listvar" value="<% !binding %>">
 <h:outputText value="#{listvar} "/>
 <a:commandButton ajaxSingle="true" value="Delete" reRender="<% !a_id %>" action="#{<% !a_remove %>}"/>
 <br />
 </a:repeat>
 </a:outputPanel>
 <br />
 <s:decorate>
 <h:selectOneMenu id="<% !ident %>" value="#{dev.nulll}" valueChangeListener="#{<% !a_listener %>}">
 <s:selectItems var="field" label="#{field.toString}" value="#{<% <all-concept> type %>}" noSelectionLabel="Please select : " />
 <s:convertEntity/>
 <a:support event="onchange" reRender="<% !a_id %>" bypassUpdates="true" />
 </h:selectOneMenu>
 </s:decorate>
 </a:region><%

(Never mind the weird <% %> holes in the XML, this is due to this being a template in generative setting, the gist of it is clear I think)

All I know is that the a:repeat gets re-rendered fine, and it is in the same outputPanel as the selectOneMenu. I confirmed that the 'dev.nulll' method gets called when the rerender happens (so the actual value of the selectOneMenu is requested), it just isn't reflected in the page...

Thanks,
Sander