<apex:page sidebar="false"  controller="BES_exportCasesToCSVController" contentType="application/vnd.ms-excel#Cases.xls">
    <apex:PageBlock >
        <apex:PageBlockTable value="{!cases}" var="case" rowClasses="odd,even" styleClass="tableClass" >
           <apex:column >
                <apex:facet name="header">Practice Name</apex:facet>
                <apex:outputText value="{!case.Practice_Name__r.Name}"/>
            </apex:column>
        </apex:PageBlockTable>
    </apex:PageBlock>
</apex:page>

This gives me excel file for the pageBlockTable contents when I execute this in Firefox 
or Google Chrome browser,but when I run this in IE 7 an error box pops up displaying following
message 
---------------------------
Windows Internet Explorer
---------------------------
Internet Explorer cannot download exportCasesToCSV from c.cs2.visual.force.com.



Internet Explorer was not able to open this Internet site.  The requested site is either unavailable or cannot be found.  Please try again later.
---------------------------
OK   
---------------------------

I need this working in IE because client uses IE7. Pls tell me any workarounf for this. I am ready to go for SControl 
also if there is no way in VisualForce

<apex:page sidebar="false"  controller="BES_exportCasesToCSVController" contentType="application/vnd.ms-excel#Cases.xls">
    <apex:PageBlock >
        <apex:PageBlockTable value="{!cases}" var="case" rowClasses="odd,even" styleClass="tableClass" >
           <apex:column >
                <apex:facet name="header">Practice Name</apex:facet>
                <apex:outputText value="{!case.Practice_Name__r.Name}"/>
            </apex:column>
        </apex:PageBlockTable>
    </apex:PageBlock>
</apex:page>

This gives me excel file for the pageBlockTable contents when I execute this in Firefox 
or Google Chrome browser,but when I run this in IE 7 an error box pops up displaying following
message 
---------------------------
Windows Internet Explorer
---------------------------
Internet Explorer cannot download exportCasesToCSV from c.cs2.visual.force.com.



Internet Explorer was not able to open this Internet site.  The requested site is either unavailable or cannot be found.  Please try again later.
---------------------------
OK   
---------------------------

I need this working in IE because client uses IE7. Pls tell me any workarounf for this. I am ready to go for SControl 
also if there is no way in VisualForce