I switched to ExtededDataModel and have it working nicely. Previously my rowKeyVar was incrementing with each row.
My current implementation is using a primary key for the this apparently.
How can I access the row number as it is rendered? I do this so my mouseover can restore the orginal color of the row onRowMouseOut.
<rich:dataTable id="pipeSearchDataTable" var="pipeSummary" value="#{pipeSearchExtendedDataModel}" styleClass="f_table" rowClasses="tr0,tr1" rows="20" rowKeyVar="rowNum" onRowMouseOver="this.className='trMouseOver'" onRowMouseOut="this.className='tr#{rowNum % 2}'">