X509Certificate timing out!

 Hi there,
I have a big problem here, in my VB.NET page, when I try to add a certificate to my HttpWebRequest. I have the following code: 
  
Dim myreq as HttpWebRequest = WebRequest.Create("https://aaa.com")
Dim certif as X509Certificate

certif = New X509Certificate("C:\cert.p12", "password")
myreq.ClientCertificates.Add(certif) 'HERE IS THE PROBLEM

 and the 'Add' call just sits there, for like 15 seconds, and then I receive en error, and in the stack trace I have[HttpException (0x80004005): Request timed out
Any clues please? 

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