weird selectOneMenu behavior in tabPanel after validation

[achildress]

I have a selectOneMenu inside a tab of a tabPanel. This selectOneMenu has a blank entry as its first selectItem (empty string value and displayed value). If I change the selection of this selectOneMenu to the blank entry select a new tab and the form is submitted, and validation fails, this selectOneMenu reverts back to its originally selected value. I would like it to remain with the blank entry selected. Is this normal JSF behavior? If not, is there something in my code below that is causing this?

tabPanel code:

 <a4j:form id="interviewform">
 <a4j:outputPanel ajaxRendered="true" id="myerrors">
 <table>
 <tr>
 <td><h:outputLabel styleClass="stdLabel" value="The following errors have occurred. Please fix them and save again." rendered="#{! empty facesContext.maximumSeverity}" /></td>
 </tr>
 </table>
 <rich:messages id="error" layout="list" styleClass="stdLabel">
 <f:facet name="errorMarker">
 <h:graphicImage value="/images/failed.gif" />
 </f:facet>
 </rich:messages>
 </a4j:outputPanel>
 <table cellpadding="0" cellspacing="0">
 <tr>
 <td align="center">
 <a4j:commandButton status="savestatus" id="saveButton" value="Save Interview" oncomplete="javascript:showErrors();" actionListener="#{DOPIntakeAdminTechInterviewBean.saveInterview}" reRender="myerrors"/>
 <a4j:status forceId="true" id="savestatus" onstart="Richfaces.showModalPanel('saveprogressmp',{width:450, top:200})" onstop="Richfaces.hideModalPanel('saveprogressmp')" />
 <h:graphicImage id="waiterrors" url="/images/waitforerrors.gif" style="display: none;"></h:graphicImage>
 </td>
 </tr>
 </table>
 <rich:spacer height="4px"></rich:spacer>
 <rich:tabPanel id="admintechinterviewtabs" switchType="ajax" style="width: 96%;" valueChangeListener="#{DOPIntakeAdminTechInterviewBean.newTabSelected}" binding="#{DOPIntakeAdminTechInterviewBean.adminTechTabs}">
 <rich:tab status="majorstatus" id="identification" label="Identification">
 <ui:include src="\interviewidentification.xhtml"/>
 </rich:tab>
 <rich:tab status="majorstatus" id="family" label="Family">
 <ui:include src="\interviewfamily.xhtml"/>
 </rich:tab>
 <rich:tab status="majorstatus" id="demographics" label="Demographics">
 <ui:include src="\blankpage.xhtml"/>
 </rich:tab>
 <rich:tab status="majorstatus" id="educationjobs" label="Education/Employment">
 <ui:include src="\blankpage.xhtml"/>
 </rich:tab>
 <rich:tab status="majorstatus" id="stg" label="STG">
 <ui:include src="\blankpage.xhtml"/>
 </rich:tab>
 <rich:tab status="majorstatus" id="criminalhistory" label="Criminal History">
 <ui:include src="\blankpage.xhtml"/>
 </rich:tab>
 <rich:tab status="majorstatus" id="complete" label="Mark Complete">
 <ui:include src="\blankpage.xhtml"/>
 </rich:tab>
 </rich:tabPanel>
 <h:inputHidden id="maximumSeverity" rendered="#{! empty facesContext.maximumSeverity}" value="#{facesContext.maximumSeverity.ordinal}" />
 </a4j:form>

Content of included facelet interviewidentification.xhtml that contains the selectOneMenu in question:

<ui:composition xmlns="http://www.w3.org/1999/xhtml"
 xmlns:ui="http://java.sun.com/jsf/facelets"
 xmlns:h="http://java.sun.com/jsf/html"
 xmlns:f="http://java.sun.com/jsf/core"
 xmlns:a4j="http://richfaces.org/a4j"
 xmlns:rich="http://richfaces.org/rich">
 <rich:panel id="intidpanel" style="width: 650px; height: 276px; overflow: auto;">
 <table>
 <tr>
 <td align="right">
 <h:outputLabel styleClass="stdLabel" value="Height: " />
 </td>
 <td align="left">
 <h:inputText required="true" id="heightFeet" label="Height Feet" value="#{IntakeOffenderBean.heightFeet}" maxlength="1" size="2" styleClass="stdTextBox">
 <f:validator validatorId="heightFeetValidator" />
 </h:inputText>
 <rich:spacer width="4px"/><h:outputLabel styleClass="stdLabel" value="ft" /><rich:spacer width="4px"/>
 <h:inputText required="true" id="heightInches" label="Height Inches" value="#{IntakeOffenderBean.heightInches}" maxlength="2" size="2" styleClass="stdTextBox">
 <f:validator validatorId="heightInchesValidator" />
 </h:inputText>
 <rich:spacer width="4px"/><h:outputLabel styleClass="stdLabel" value="in" />
 </td>
 <td align="right">
 <h:outputLabel styleClass="stdLabel" value="Body Build: " />
 </td>
 <td align="left">
 <h:selectOneMenu required="true" label="Body Build" id="bodyBuildCombo" value="#{IntakeOffenderBean.bodyBuild}">
 <f:selectItems value="#{CodeCacheBean.getASICodes$['CMBODBLD'][true]}"/>
 </h:selectOneMenu>
 </td>
 </tr>
 </table>
 </rich:panel>
</ui:composition>