procedure TFormMain.mvDocImagesKeyUp(Sender: TObject; var Key: Word; Shift: TShiftState);
var
  bm: TIEBitmap;
begin
  case Key of
    VK_C:
      begin
        if Shift*[ssShift, ssAlt, ssCtrl] = [ssCtrl] then
        begin
          bm := mvDocImages.GetTIEBitmap(mvDocImages.SelectedImage);
          try
            if not bm.CopyToClipboard() then // error here!!!
              Application.MessageBox('Copy to Clipboard failed.',
                PChar(Application.Title), MB_OK + MB_ICONSTOP + MB_TOPMOST);
          finally
            bm.Free;
          end;
        end;
      end;
  end;
end;