Layout problem of scrollableDataTable with sort and reRender

[darmstadter]

i am using a alarm table:scrollable dataTable with sortMode="single".
Each alarm can be acknowledged through a checkbox, and while it is deleted from the data table.
The problem of layout occurs after acknowledge the alram. But if you don't click the head(sorting)previously
the layout works fine. Dose it mean, if the sort of the table is active, reRender the table again, the layout is not alright.

<rich:scrollableDataTable id="messagePaneId"
 height="#{layoutBean.messageTblHeight}"
 width="#{layoutBean.messageTblWidth}"
 value="#{appData.messages}" var="message"
 rows="40" rowKeyVar="rkv" sortMode="single"
 frozenColCount="1"
 rendered="${ppData.messageCount>0)}"

 rowClasses="taskRows" columnClasses="taskColumns">
 <rich:column id="date" style="#{message.messageStyle}">
 <f:facet name="header">
 <h:outputText value="Date"/>
 </f:facet>
 <h:outputText value="#{message.dateString}" />
 </rich:column>
 <rich:column id="text" width="178" style="#{message.messageStyle}">
 <f:facet name="header">
 <h:outputText value="Text"/>
 </f:facet>
 <h:outputText value="#{message.text}" title="#{message.text}"/>
 </rich:column>
 <rich:column id="category" style="#{message.messageStyle}">
 <f:facet name="header">
 <h:outputText value="Category"/>
 </f:facet>
 <h:outputText value="#{message.category}"
 title="#{message.category}"/>
 </rich:column>
 <rich:column id="severity" width="60" style="#{message.messageStyle}">
 <f:facet name="header">
 <h:outputText value="Severity"/>
 </f:facet>
 <h:outputText value="#{message.severity}" />
 </rich:column>
 <rich:column id="portName" width="90" style="#{message.messageStyle}">
 <f:facet name="header">
 <h:outputText value="Port"/>
 </f:facet>
 <h:outputText value="#{message.portName}"
 title="#{message.portName}"/>
 </rich:column>
 <rich:column sortable="false" width="90" style="#{message.messageStyle}">
 <f:facet name="header">
 <h:outputText value="Acknowledged"/>
 </f:facet>
 <h:selectBooleanCheckbox id="messageAckCheck#{message.id}" value="#{message.acknowledged}"
 onclick="startWait();this.disabled=true;sendAckMessage#{message.id}()">
 <a4j:jsFunction name="sendAckMessage#{message.id}" action="#{mainBean.messageAcknowledged}"
 reRender="messagePane" ajaxSingle="true" oncomplete="stopWait();">
 <a4j:actionparam name="id" value="#{message.id}" />
 </a4j:jsFunction>
 </h:selectBooleanCheckbox>
 </rich:column>

whether the data list of scrollableDataTable can not changed during with sort?