I downloaded some books from http://books.google.de/ as pdf.
They display perfectly on a linux box using acroreader 8.0 or evince.
The iLiad does not show them but blinks a while if I want to access them from the content lister. I tried to repair tha file using pdftk but with no better result.
Starting ipdf manually from the shell
gives the error code 3
Error: Document has not the mandatory ennding %EOF

tail shows that there is an %EOF at the end of the file

Any ideas?

Google's help page (http://books.google.com/support/bin/answer.py?answer=44668&ctx=sibling) just says Images in our PDFs are highly compressed but Adobe's Digital Edtions FAQ is a bit more forthcoming: Why don't some Google Book PDF files work with Digital Editions?
Google is using JPEG2000 image compression to compress certain kinds of color-based page images, and this format is not supported by Digital Editions 1.0.

Google says that xpdf (with JBIG2 patch) reads its PDFs, so there is a chance that an updated ipdf could too.