Get All Users in an Active Directory Group

Question

I'm using the following code sample to get a list of all users in a specified AD group (in this case, all users in the "Domain Users" group). My listed code works great, with one exception: it won't return users who have their primary group set to "Domain Users". How can I get a list of all users in the group, including those who have it set as their primary group?

Private Sub GetUsers()

    Dim groupSearcher As New DirectorySearcher
    Dim groupSearchRoot As New DirectoryEntry("LDAP://OU=Users,DC=domain,DC=com")

    With groupSearcher
        .SearchRoot = groupSearchRoot
        .Filter = "(&(ObjectClass=Group)(CN=Domain Users))"
    End With

    Dim members As Object
    members = groupSearcher.FindOne.GetDirectoryEntry.Invoke("Members", Nothing)

    For Each member As Object In CType(members, IEnumerable)
        Console.WriteLine(New DirectoryEntry(member).Name.Remove(0, 3))
    Next
End Sub