Fancybox not showing streamed image correctly

I've got an ASPX page that streams jpeg's. It sets the content type and then writes to the response stream. If I view the images directly they work a treat, but if I use Fancybox 1.2.6 I get the following.

Using fancybox 1.2.1 the images do show.

Here is the code that is pushing out the image.

using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
        {
            using (Stream responseStream = response.GetResponseStream())
            {
                using (Image outImg = Image.FromStream(responseStream))
                {
                    Response.Clear();
                    Response.ContentType = "image/jpeg";
                    outImg.Save(Response.OutputStream, ImageFormat.Jpeg);
                }
            }
        }

Any help?