Originally Posted by Hadrien
The last file was a poorly formatted graphic novel.
Stanza does not support images at all. From its FAQ
Help! Stanza isn't displaying my graphics/tables/bullet lists/etc.
That is by design. Stanza removes nearly all of the formatting of the text that it reads. This is in order to maximize the flexibility of the user interface, as well as maximize the number of formats we can support. As mentioned above, this makes Stanza unsuitable for content where graphics or formatting is an intrinsic part of the reading experience.
I tried to read a PDF, and nothing shows up at all
Some PDFs do not actually contain any text that is readably by a computer, but instead contain a series of pictures of text. You can test to see if this is the case by opening the PDF in a PDF viewer (like Preview.app or Adobe Acrobat), and trying to select the text with the selection tool. If you are unable to highlight any individual letters in the text, then the document is simply a collection of images, and will be unreadable by Stanza.