Web browser control and cookies

I have a problem with managing WebBrowser and cookies.

First of all, what happens when you switch to a regular web browser (IE9 in my case):

1.1. I open the web page http://www.gmail.com .

I enter my username / password,
I leave the "Stay signed in" checkbox unchecked and click "Login",
IE9 opens my GMail page with all my emails. This is normal.

1.2. There are many links at the top of the GMail page such as Calendar, Documents, etc.

When I click the Documents link, my Documents page opens in a separate tab in IE9. There is no additional login information as specified by the name / psw. It's also good.

Now what happens when I iterate all of this in a WebBrowser control (I created a very simple VB.NET application with one WebBrowser control in it).

2.1. The following code is executed in the form load event:

Private Sub MyForm_Load(sender As System.Object, e As System.EventArgs)
    Me.MyWebBrowser.Navigate("http://www.gmail.com")
End Sub

2.2. I enter my GMail login details (name and psw) in the WebBrowser control,

2.3. When I click the Documents link, a new instance of IE9 opens,

2.4. Instead of showing a list of my documents, Google asks me to log into the IE9 window again. What for? Why do I need to enter my credentials again?

I think there is something wrong with cookies and they are not set correctly in step 2.2. Do you have any idea what is wrong and what needs to be done to set the cookie correctly?

Thanks in advance,
Sal

Additional Information:

I have a WebBrowser NewWindow event function implemented as:

Private Sub MyWebBrowser_NewWindow(sender As System.Object, e As System.ComponentModel.CancelEventArgs) Handles MyWebBrowser.NewWindow
    Dim CookiesArr As String() = MyWebBrowser.Document.Cookie.Split(";")
    For Each Cookie In CookiesArr
        Dim Idx As Long = Cookie.IndexOf("=")
        If Idx <> -1 Then
            Dim CookieName As String = Cookie.Substring(0, Idx).Trim
            Dim CookieValue As String = Cookie.Substring(Idx + 1).Trim
            InternetSetCookie("http://www.google.com", Nothing, CookieName + " = " + CookieValue + "; expires = Sat,05-Jan-2013 00:00:00 GMT")
        End If
    Next
End Sub

      

        
        
        
      

    

I believe the InternetSetCookie () method should store cookies permanently in the "C: \ Users \ Administrator \ AppData \ Roaming \ Microsoft \ Windows \ Cookies" directory for reuse when a Google page is opened that requires authorization.