Hi!
I am using RichFaces 3.3.0 with JBoss Seam.
I created a scrollableDataTable the following way:
<rich:scrollableDataTable value="#{dat.lstElements}" var="_elem" sortMode="single" rows="100" >
<rich:column id="colName">
<f:facet name="header">Title</f:facet>
<h:outputText value="#{_elem.strName}" />
</rich:column>
(three more columns)
</rich:scrollableDataTable>
This column designed in order to implement columns resize. Ir represents "freespace" for resize operations. You could make it invisible via css.