Richfaces datatable not refreshing a column after sorting - ajax

Question

I have a datatable with custom sorting. It sorts the array containing my data and then the table is refreshed via ajax call. The table has multiple columns with simple text in it, and an additional column with command button and command links. My problem is, that this buttons and links are not refreshed. It means that if I click the button on the second row, it affects the element which was in the second row before sorting.
This is the page code:
<h:body>
<h:form class="page_frame">
<a4j:jsFunction name="sortTable" render="data_table#body"
actionListener="#{MyBean.getFilteredData()}" >
<a4j:param name="param1" assignTo="#{MyBean.newSortBenchmark}"/>
</a4j:jsFunction>
<rich:dataTable value="#{MyBean.getFilteredData()}" var="data" id="data_table"
rowClasses="odd-row, even-row" styleClass="even_odd"
style="width: 900px;">
<rich:column >
<f:facet name="header">
<span onclick="sortTable('name')">Name</span><br/>
</f:facet>
<h:outputText value="#{data.name}"/>
</rich:column>
//more similar columns with sorting
<rich:column>
<f:facet name="header">Start/Stop</f:facet>
<a4j:commandButton value="Start" action="#{MyBean.startProcess(data)}"
rendered="#{!data.processRunning}"
render="data_table#body"
execute="#this" style="width: 100%" >
</a4j:commandButton>
<a4j:commandButton value="Stop" action="#{MyBean.stopProcess(data)}"
rendered="#{data.processRunning}"
render="data_table#body"
execute="#this" style="width: 100%" >
</a4j:commandButton>
</rich:column>
<rich:column>
<f:facet name="header">Actions</f:facet>
<a4j:region>
<a4j:commandLink action="#{MyBean.showDetails(data)}" oncomplete="#{rich:component('detailsPanel')}.show()" render="details_table" >
<h:graphicImage id="details_image" name="details.png" library="images" style="border:0" />
<rich:tooltip followMouse="true" target="details_image" value="Details" />
</a4j:commandLink>
</a4j:region>
//more similar command links, also not working
</rich:column>
</rich:dataTable>
</h:form>
</h:body>
And the filtering is done by:
Collections.sort(dataList, new dataComparator(sortBenchmark));