I don't see the issue in the Dicom demo either.  Here are two simple code samples where I get an access violation with CT-MONO2-16-ankle.dcm:
ImageEnVect1.IO.LoadFromFile('c:\test\image\CT-MONO2-16-ankle.dcm');
ImageEnVect1.IO.SaveToFile('c:\test.gif');
And this:
procedure TForm1.FormCreate(Sender: TObject);
var
  io: TImageEnIO;
begin
  io := TImageEnIO.Create(nil);
  try
    io.LoadFromFile('c:\test\image\CT-MONO2-16-ankle.dcm');
    io.SaveToFileGIF('c:\test.gif');
  finally
    io.Free;
  end;
end;
First chance exception at $75699617. Exception class EAccessViolation with message 'Access violation at address 005EE888 in module 'Project1.exe'. Write of address 00130001'. Process Project1.exe (1396)