Changed the way the attribute and functions were written and now it works perfectly.

Code:
        Private Class GDI32

            Public Shared SRCCOPY As Integer = &HCC0020
            ' BitBlt dwRop parameter
            <DllImport("gdi32.dll")> Public Shared Function BitBlt(ByVal hObject As IntPtr, ByVal nXDest As Integer, ByVal nYDest As Integer, ByVal nWidth As Integer, ByVal nHeight As Integer, ByVal hObjectSource As IntPtr, ByVal nXSrc As Integer, ByVal nYSrc As Integer, ByVal dwRop As Integer) As Boolean
            End Function

            <DllImport("gdi32.dll")> Public Shared Function CreateCompatibleBitmap(ByVal hDC As IntPtr, ByVal nWidth As Integer, ByVal nHeight As Integer) As IntPtr
            End Function

            <DllImport("gdi32.dll")> Public Shared Function CreateCompatibleDC(ByVal hDC As IntPtr) As IntPtr
            End Function

            <DllImport("gdi32.dll")> Public Shared Function DeleteDC(ByVal hDC As IntPtr) As Boolean
            End Function

            <DllImport("gdi32.dll")> Public Shared Function DeleteObject(ByVal hObject As IntPtr) As Boolean
            End Function

            <DllImport("gdi32.dll")> Public Shared Function SelectObject(ByVal hDC As IntPtr, ByVal hObject As IntPtr) As IntPtr
            End Function
        End Class 'GDI32
       _

        '/ <summary>
        '/ Helper class containing User32 API functions
        '/ </summary>
        Private Class User32
            <StructLayout(LayoutKind.Sequential)> _
            Public Structure RECT
                Public left As Integer
                Public top As Integer
                Public right As Integer
                Public bottom As Integer
            End Structure 'RECT

        <DllImport("user32.dll")>Public Shared Function GetDesktopWindow() As IntPtr
            End Function
            <DllImport("user32.dll")> Public Shared Function GetWindowDC(ByVal hWnd As IntPtr) As IntPtr
            End Function

            <DllImport("user32.dll")> Public Shared Function ReleaseDC(ByVal hWnd As IntPtr, ByVal hDC As IntPtr) As IntPtr
            End Function

            <DllImport("user32.dll")> Public Shared Function GetWindowRect(ByVal hWnd As IntPtr, ByRef rect As RECT) As IntPtr
            End Function
        End Class