When you select a .png formatted image for a web page, Spider Writer informs you that the .png formatted image is an invalid format. If you tell it to continue with the selection it adds the image but it provides the html code with incorrect height and width sizes for that image. Therefore, I have to open/browse the .png formatted image in paintshop, record the height and width and then go back into the Spider Writer html code and change the height and width to what they really should be.
I hope this makes sense!