I'll have to look into that, I tested with books that I purchased from O'Reilly and many of the others that I came across online. this is an example of a book that I tested before uploading:
restfulwebapis.org/RESTful_Web_Serv
...
Please tell me what the software you used so I can further investigate the problem.
Based on the code, if the file 'META-INF/encryption.xml' exists in the epub file, it will print that page; try deleting the file from the epub archive.
hope this helps