I am trying to get a binary file into my XML document from inside my VFP .prg and I think I am seeing an interface incompatibility. What do you think?

Fails with
"OLE IDispath exception code 0 from msxml4.dll: Error parsing 'RIFFp0 ' as bin.base64 datatype"

I thought this was supposed to convert binary automatically to base64?

oSendDoc =  CreateObject("Msxml2.FreeThreadedDOMDocument.4.0")
oSendDoc.SetProperty("SelectionLanguage" , "XPath")
oRootElement = oSendDoc.createElement("xml")
oRoot = oRootElement
oSendDoc.appendChild(oRoot)
oXmlPI = oSendDoc.createProcessingInstruction("xml", "version='1.0'")
oSendDoc.insertBefore(oXmlPI, oSendDoc.childNodes(0))
oEnvElement = oSendDoc.createElement("envelope")
oEnvElement.DataType = "bin.base64"
oEnvElement.NodeTypedValue = FileToStr("c:\winnt\media\notify.wav")
oRoot.appendChild( oEnvElement )
oSendDoc.Save("it.xml")