Originally Posted by ATDrake
In which case, your problem seems to be with <opf:metadata>. I'm not sure that <metadata> is actually in the opf: namespace, but even if it were, you would have to put the xmlns for opf at least one level above under <package>, rather than calling it from within the namespaced tag even as you're defining it.
Hope this helps.
Since this is Calibre output, how do I control the placement?