extended ascii delimiters when when writing to outputstream

[brrrdog]

Whenever I write to Response.Outputstream after doing a
plain response.write, I get a delimiter between the two
writes that is made up of three extended ascii chars
(decimal equivalents 239, 187, 191). This doesn't seem to
upset the browser but i'm wondering what this sequence is
for? Is there a way to turn it off?
Example: Excuting the following code...
private void Page_Load(object sender, System.EventArgs e)
{
XslTransform xslt = new XslTransform();
xslt.Load(Server.MapPath("XSLTFile1.xslt"));
XmlDataDocument xml = new XmlDataDocument();
xml.Load(Server.MapPath("XMLFile1.xml"));
Response.Write("Before Outputstream");
xslt.Transform(xml.CreateNavigator
(),null,Response.OutputStream);
Response.Write("After outputstream");
}

//yields...
Before OutputstreamxslResultsAfter outputstream
//the same thing with the decimal values substituted
for //the extra chars...
<239><187><191>Before
Outputstream<239><187><191>xslResultsAfter outputstream