I copied the following code from the sample that you sent me to my code and it now works as it should. Thank you once again.
previously I had:
case "jpeg":
case "jpg":
case "png":
case "bmp":
//Add a page to the document
PdfPage page = pdfDocument.Pages.Add();
//Create PDF graphics for the page
PdfGraphics graphics = page.Graphics;
PdfBitmap image = new PdfBitmap(stream);
//Draw the image
graphics.DrawImage(image, 0, 0);
break;