New Post: HtmlRender.Render generates unformatted image

Hi I am facing a similar issue. Here is my function to render image:

private void SaveImageFromHtml(MvcHtmlString html)
        {
            var decodedHtml = html.ToHtmlString();
            var cssData = HtmlRenderer.CssData.Parse(GetStyleSheet(), true);
            Image image = HtmlRender.RenderToImage(decodedHtml, cssData: cssData);

            var bitmap = new Bitmap(image);
            bitmap.Save(@"D:\Test.png", ImageFormat.Png);
        }

The GetStyleFunction() is simple:

private string GetStyleSheet()
        {
            return @".inner {
                        width:960px;
                        margin: 0px auto;
                    }

                    .inner .left-col {
                        width: 200px;
                        height:1200px;
                        background-color: #2c2c2c;
                        display:block;
                        font-family:Tahoma, Geneva, sans-serif;
                        font-size:40px;
                        color:#999;
                        text-align:center;
                        float:left;
                    }
      }

But the image is produced with no css styling being applied. I am not sure what is happening. I am using version 1.4.14.0
Any pointers will be much appreciated!