Someone is eating my <?xml version="1.0"?> returning an Excel XML in Asp.net MVC - asp.net-mvc

Question

I'm playing with VB XML literals for returning and Excel XML file.
the problem is that the first line containing <?xml version="1.0"?> does not make to the download.
Here is the code:
Public Class ReservasController
Function Test()
Response.Clear()
Response.AddHeader("Content-Disposition", "attachment; filename=test.xml")
Response.ContentType = "application/vnd.ms-excel"
Response.ContentEncoding = System.Text.Encoding.GetEncoding("utf-8")
Response.Write(GetXML())
''//This works:
''//Response.Write("<?xml version=""1.0""?>" + GetXML().ToString())
Response.End()
Return Nothing
End Function
The GetXML method is very simple:
Private Function GetXML()
Return <?xml version="1.0"?>
<?mso-application progid="Excel.Sheet"?>
<Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet"
xmlns:o="urn:schemas-microsoft-com:office:office"
xmlns:x="urn:schemas-microsoft-com:office:excel"
xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet"
xmlns:html="http://www.w3.org/TR/REC-html40">
<DocumentProperties xmlns="urn:schemas-microsoft-com:office:office">
<Author>Bizcacha Excel Generator</Author>
<LastAuthor>Bizcacha Excel Generator</LastAuthor>
<Created>20100101</Created>
<Company>Bizcacha</Company>
<Version>1</Version>
</DocumentProperties>
<ExcelWorkbook xmlns="urn:schemas-microsoft-com:office:excel">
</ExcelWorkbook>
<Styles>
<Style ss:ID="Default" ss:Name="Normal">
<Alignment ss:Vertical="Bottom"/>
<Borders/>
<Font/>
<Interior/>
<NumberFormat/>
<Protection/>
</Style>
</Styles>
<Worksheet ss:Name="title">
<Table x:FullColumns="1" x:FullRows="1" ss:DefaultRowHeight="15">
<Column ss:Width="100"/>
<Column ss:Width="100"/>
<Row ss:AutoFitHeight="0">
<Cell ss:StyleID="Default"><Data ss:Type="String">Hello</Data></Cell>
<Cell ss:StyleID="Default"><Data ss:Type="String">World</Data></Cell>
</Row>
</Table>
</Worksheet>
</Workbook>
End Function
End Class

Answer 1

Looking at it, would it have anything to do with returning a string in which quotes are used...why not replace those quotes with Chr(34) which is the ASCII code for the " ...as an example:
Const Char DblQuote As String = Chr(34)
Private Function GetXML()
Return "<?xml version=" & DblQuote & "1.0" & DblQuote & "?>" & vbCrLf _
& "<?mso-application progid=" & DblQuote & "Excel.Sheet" & DblQuote & "?>" & vbCrLf _
and so on...
What do you think?
Hope this helps,
Best regards,
Tom.

Answer 2

Doing XML literals was a pain, so I moved back to string concatenation.