Moved to InDesign EPUB forum
OR the subject line could have been, "Incorrect editing of metadata by customer lead to epub validation failure! News at 11!"
In the fall update for InDesign CC we've added the xmlns:opf namespace to help avoid this common user error - InDesign does not write anything that requires it so we never put it in.
Architect, InDesign Engineering
OR the subject could have been "Adobe engineers rush to meet marketing window and feverishly work on patches for known defects and product inadequacy while marketing promises the world to Adobe customers." Stop blaming the customer—particularly if you are a member of the guilty party. I've been in engineering 40 years and I finally kissed MS goodbye for Apple with just one arrogant attitude too many at MS. I took a company and a college with me too. You're a powerhouse at the moment, but so was Tandem Computers before a little upstart PC upstart bought them out. Corel is on your butt and closing the gap. They aren't there, but they are doing what Borland did to Microsoft and affecting your prices, your profits, and making you come up with all sorts of "creative" plans to maintain your lead. If your CEO saw your cantankerous reply to a customer post he'd probably put you in timeout at annual review time "oh smart one". Why don't you "move" this one to your upper management.