I created an ePub via InDesign and edited it using Calibre. It passes Calibre's error check as well as the IDPF validator testing and Smashword's AutoVetter (during upload).
Upon review though, Smashword rejected the file with the following information:
We have run EPUBcheck on your file, and unfortunately, it has not passed validation. The errors found were:
Undecleared prefix: calibre
URL expected instead of calibre:
Please correct these issues and upload your file again.
There are a number of references to calibre in the content.opf file, but I don't know what is safe to change and what's not there.
Any idea how to get the file to finish passing Smashword's testing?