What does 'You should pass XmlResolver to Transform() method' mean???

[Showjumper]

I've got the following code. But the XSLTransform line is underlined by the
blue squiggle and vs tells me
c:\inetpub\wwwroot\Sites\RiderDesign\articles\test.aspx.vb(37): 'Public Sub
Transform(input As System.Xml.XPath.IXPathNavigable, args As
System.Xml.Xsl.XsltArgumentList, output As System.IO.Stream)' is obsolete:
'You should pass XmlResolver to Transform() method'

What the heck does this mean? Thanks...

Dim XMLDoc As New XmlDocument
XMLDoc.Load(Server.MapPath("files/since1968_interview_zeldman.xml"))
Dim XSLTrans As New Xsl.XslTransform
XSLTrans.Load(Server.MapPath("files/nitf-interview-bio-to-html.xsl"))
Dim ms As New MemoryStream
XSLTrans.Transform(XMLDoc, Nothing, ms)
ms.Seek(0, SeekOrigin.Begin)
Dim sr As New StreamReader(ms)
PageContent.Text = sr.ReadToEnd()
sr.Close()