HttpWebRequest.GetResponse throws a WebException (same code in 1.1 works OK) by orbit1

This code:

Dim Url AS String = "http://www.amazon.com"
Dim req1 As HttpWebRequest
req1.CookieContainer = New CookieContainer
req1.AllowAutoRedirect = True
Dim res1 As HttpWebResponse
req1 = CType(HttpWebRequest.Create(Url), HttpWebRequest)
res1 = CType(req1.GetResponse(), HttpWebResponse)

works in 1.1 but throws this Exception in 2.0:

{System.Net.WebException}
    [System.Net.WebException]: {System.Net.WebException}
    _className: Nothing
    _COMPlusExceptionCode: -532459699
    _data: Nothing
    _dynamicMethods: Nothing
    _exceptionMethod: Nothing
    _exceptionMethodString: Nothing
    _helpURL: Nothing
    _HResult: -2146233079
    _innerException: Nothing
    _message: "The server committed a protocol violation"
    _remoteStackIndex: 0
    _remoteStackTraceString: Nothing
    _source: Nothing
    _stackTrace: {System.Array}
    _stackTraceString: Nothing
    _xcode: -532459699
    _xptrs: 0
    Data: {System.Collections.ListDictionaryInternal}
    HelpLink: Nothing
    HResult: -2146233079
    InnerException: Nothing
    IsTransient: False
    Message: "The server committed a protocol violation"
    Source: "System"
    StackTrace: " at System.Net.HttpWebRequest.CheckFinalStatus(Boolean mustThrow)
at System.Net.HttpWebRequest.GetResponse()
at bs.Details.GetHTMLFromUrl(String URL) in C:\Net\Source\ORbitter2\bsAmazon\Details.vb:line 321"
    TargetSite: {System.Reflection.RuntimeMethodInfo}