there is the reason to use GetDIBBits. Exactly for network. Gdiplus doesn't invert bitmap content during BitBlt, fo example.

Same shit. Save method creates file, but doesn't write. And the very strange is GDI+ error. As soon as I know it doesn't return any error besides cases when the pointer to Image raw data is not returned. In fact, GDI+ deals with windows context (Device Context) of the control where image is shown. Therefore, it might be GDI+ API can't get the control's handle or doesn't has an access right to the control.. maybe .NET blocks the access to its controls from outside dll request. From other side all components are in the same thread, though maybe this Save operation opens new thread???? Any idea?