XML error in ElementType, attribute tag in generated XML spreadsheet

[pnschofield]

I'm getting the following error in Excel when I attempt to open an XML
spreadsheet I'm generating:

XML ERROR in PivotTable
REASON: Missing Tag
FILE: C:\projects\AdShuffle\AdShuffle.CommandCenter\xml\ReportOutput.xml
GROUP: ElementType
TAG: attribute

Here's the schema section of my spreadsheet:

<s:Schema xmlns:s="uuid:BDC6E3F0-6DA3-11d1-A2A3-00AA00C14882">
<s:ElementType s:name="row" s:content="eltOnly">
<s:attribute s:type="Col1" />
<s:attribute s:type="Col2" />
<s:attribute s:type="Col3" />
<s:attribute s:type="Col4" />
<s:attribute s:type="Col5" />
<s:attribute s:type="Col6" />
<s:attribute s:type="Col7" />
<s:attribute s:type="Col8" />
<s:attribute s:type="Col9" />
<s:attribute s:type="Col10" />
<s:attribute s:type="Col11" />
<s:attribute s:type="Col12" />
<s:attribute s:type="Col13" />
<s:attribute s:type="Col14" />
<s:attribute s:type="Col15" />
<s:attribute s:type="Col16" />
<s:attribute s:type="Col17" />
<s:attribute s:type="Col18" />
<s:attribute s:type="Col19" />
<s:attribute s:type="Col20" />
<s:attribute s:type="Col21" />
<s:attribute s:type="Col22" />
<s:attribute s:type="Col23" />
<s:attribute s:type="Col24" />
<extends s:type="rs:rowbase"/>
</s:ElementType>
<s:AttributeType s:name="Col1" rs:name="Client"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col2" rs:name="ActivityDate"
xmlns:rs="urn:schemas-microsoft-com:rowset">
</s:AttributeType>
<s:AttributeType s:name="Col3" rs:name="Impressions"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col4" rs:name="Clicks"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col5" rs:name="Spend"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col6" rs:name="CampaignRate"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col7" rs:name="PackageName"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col8" rs:name="Location"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col9" rs:name="Address"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col10" rs:name="CreativeName"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col11" rs:name="ClickthroughRate"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col12" rs:name="CostBasis"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col13" rs:name="CreativeID"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col14" rs:name="PlacementID"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col15" rs:name="CampaignName"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col16" rs:name="CampaignCost"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col17" rs:name="CreativeType"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col18" rs:name="PublisherName"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col19" rs:name="PlacementName"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col20"
rs:name="CampaignActivationStartDate"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col21"
rs:name="CampaignActivationEndDate"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col22" rs:name="RepeatConversion"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col23" rs:name="ViewConversion"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
<s:AttributeType s:name="Col24" rs:name="ClickConversion"
xmlns:rs="urn:schemas-microsoft-com:rowset" />
</s:Schema>

Does anybody see a problem with the schema?

Paul