[snip]

Alexander, thank you for your help with this roadblock issue.

The answer to this is in the declaration of the call. In VB.NET (VB6 Longs are not VB.NET Longs) I believe the bitmask was skewed due to the incorrect casting of longs in .NET. Integer or better yet intPtr should be used. Plamen Ivanov shows a concise method in VB.NET to cast to IntPtr in this post:

The call should looks like so:

    <DllImport("User32.dll", EntryPoint:="GetWindowLong")> _
    Friend Shared Function GetWindowLong(ByVal HWND As IntPtr, ByVal Index As Integer) As Integer
    End Function

Thanks again to everyone who helped me on this,