Archive Image Preview

When I distribute my fonts from the site, I like to include a couple of images. One graphic to preview the font (sort of a promotion jpeg image) and another screen grab of the complete character set (a png image). Of course, I zip them up and put them in the archive.

When the font is viewed, there is a list of files in the archive. I can view the text files just fine, but the .jpg and .png images appear to be sent as text instead of binary. So I just get a whole bunch of non-sensical characters printed across the screen.

Is there any solution for this?