Issues Implementing the displayTag

HI,

I am facing an issue while implementing the DisplayTag in JSP. The purpose of using the displatag was to implement pagination, column sorting as well as export feature on the table view in JSP.
Now the problem is that the export feature of the displaytag is not working as it is supposed to. But the pagination as well as column sorting is working fine.
The links for the export feature are displayed below the table in the jsp.Also when i click on export button i get the windows prompt to either save this excel file or open, Now the problem is that the excel file has no data in it, the file size is 0 kb

Following are the code snippets which i implemnted in my code

Server : Red Hat Linux
Application Server : Pramati

=================================================================
WEB.XML

displaytag.properties

sort.amount=list
paging.banner.placement=top
paging.banner.all_items_found=
paging.banner.some_items_found=
paging.banner.one_item_found=
paging.banner.onepage=
paging.banner.full=<div class="pagelinks" align="right"><a href={1}><img src="../images/first.gif"></a><a href={2}><img src="../images/prev.gif"></a>{0}<a href={3}><img src="../images/next.gif"></a><a href={4}><img src="../images/last.gif"></a></div>
paging.banner.first=<div class="pagelinks" align="right"><a href={1}><img src="../images/first.gif"></a><a href={2}><img src="../images/prev.gif"></a> {0} <a href={3}><img src="../images/next.gif"></a><a href={4}><img src="../images/last.gif"></a></div>
paging.banner.last=<div class="pagelinks" align="right"><a href={1}><img src="../images/first.gif"></a><a href={2}><img src="../images/prev.gif"></a> {0} <a href={3}><img src="../images/next.gif"></a><a href={4}><img src="../images/last.gif"></a></div>
export.types=csv excel rtf
export.excel=true
export.csv=true
export.rtf=true
export.excel.class=org.displaytag.export.excel.DefaultHssfExportView
export.csv.class=org.displaytag.export.CsvView
export.rtf.class=org.displaytag.export.DefaultRtfExportView
export.excel.filename=data.xls
export.csv.filename=data.csv
export.rtf.filename=data.rtf

JSP Page

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<display:table cellpadding="1" cellspacing="0" class="dataTable" export="true"  pagesize="5" name="list" style="width:100%" id="list_l1">

<display:column property="CASE_NO" title="Case #" sortable="true" media="excel csv"/>
<display:column property="CUSTOMER_NUMBER" title="Customer #" sortable="true"/>
<display:column property="CUSTOMER_NAME" title="Customer Name" sortable="true"/>
<display:column property="DISPUTE_OPEN_DATE" title="DISPUTE OPEN DATE" sortable="true"/>
<display:column property="DISPUTE_CLOSED_DATE" title="DISPUTE CLOSED DATE" sortable="true"/>
<display:column property="DISPUTE_DAYS" title="DISPUTE DAYS" sortable="true"/>
<display:column property="INV_CLOSED_DATE" title="INV_CLOSED_DATE" sortable="true"/>
<display:column property="FINAL_RESOLUTION" title="FINAL_RESOLUTION" sortable="true"/>
<display:column property="DISPUTE_CATEGORY" title="DISPUTE_CATEGORY" sortable="true"/>
<display:column property="DISPUTE_REASON" title="DISPUTE_REASON" sortable="true"/>
<display:column property="CASE_OWNER" title="CASE_OWNER" sortable="true"/>
<display:column property="ACCOUNT_OWNER" title="ACCOUNT_OWNER" sortable="true"/>
<display:column property="REGION_NAME" title="REGION_NAME" sortable="true"/>
<display:column property="BRANCH_NAME" title="BRANCH_NAME" sortable="true"/>
<display:column property="ACCOUNT_TYPE_ID" title="ACCOUNT_TYPE_ID" sortable="true"/>
</display:table>
<%
}
l_objCaseLog.debug("After .<display:column>");
%>
</form>
</body>
</html>

View Source of JSP to see the Export Links generated

<div class="exportlinks">Export options: 
<a href="/sbm/bpmportal/management/CaseCloseResult.jsp?todate=&DispReason=Select&region=Select&6578706f7274=1&fromdate=&d-49520-e=1&textField1=&textField2=&DispCat=Select&branch=Select&caseowner=Select&hid66=pass&textField4="><span class="export csv">CSV </span></a>|
<a href="/sbm/bpmportal/management/CaseCloseResult.jsp?todate=&DispReason=Select&region=Select&6578706f7274=1&fromdate=&d-49520-e=2&textField1=&textField2=&DispCat=Select&branch=Select&caseowner=Select&hid66=pass&textField4="><span class="export excel">Excel </span></a>|
<a href="/sbm/bpmportal/management/CaseCloseResult.jsp?todate=&DispReason=Select&region=Select&6578706f7274=1&fromdate=&d-49520-e=3&textField1=&textField2=&DispCat=Select&branch=Select&caseowner=Select&hid66=pass&textField4="><span class="export xml">XML </span></a>|
<a href="/sbm/bpmportal/management/CaseCloseResult.jsp?todate=&DispReason=Select&region=Select&6578706f7274=1&fromdate=&d-49520-e=5&textField1=&textField2=&DispCat=Select&branch=Select&caseowner=Select&hid66=pass&textField4="><span class="export pdf">PDF </span></a>|
<a href="/sbm/bpmportal/management/CaseCloseResult.jsp?todate=&DispReason=Select&region=Select&6578706f7274=1&fromdate=&d-49520-e=6&textField1=&textField2=&DispCat=Select&branch=Select&caseowner=Select&hid66=pass&textField4="><span class="export rtf">RTF </span></a></div>

</form>
</body>
</html>

I would really appreciate if i would get some help in this regards.

Thanks & Regards
Virendra P.Sawant