PIL and Windows file formats?

[Christopher Lee]

Is the PIL directory part of your python path?  The png image plugin is
only loaded automatically if the PIL directory is on your pythonpath.

[Are you perhaps using PIL as a package (as in import PIL.Image )?]

You can load the plugin yourself.  In a message on the image-sig list, /F
suggested: 

    from PIL import Image, PngImagePlugin # etc.

-chris