I don't know if the problem was the BeBook's rendering engine, Sibil, Calibre, or my ePub's quality (or all of the above), but it clearly underscores the need for better tools for compliance and conversion. I wrote an
essay on my site about the need in this industry for more devices that read all the popular formats, leaving the consumer to choose their device based on price and features, not on which formats it did or did not read. But conversion engines need to work first, and files need to be compliant in the first place.
I'll have to look closer at my ePub conversions, to make sure they are fully compliant with IDPF standards before I send them out.