Originally Posted by pdurrant
There are certainly some problems with the zip structure of some epub books.
That simply unzipping and rezipping causes a problem in ADE does suggest that there's some problem in this book's zip structure that might also be causing problems in the dedrm process.
It turns out that this is a known problem to do with non-ascii characters in file names, and is a bug in the ineptepub script. I think a fix should be out soonish.
Meanwhile, it is possible to work around the problem by unzipping the epub in question, and changing the file names and the references to the files in the opf file and the encryption.xml file