I have made my ebooks with Calibre too. Yes, I had the problem with AdobeViewer as well as with FBreader. One of the books I was reading was
this. I don't remember whether I downloaded it as epub or (more likely) as PDF and then converted it to epub with Calibre.
Bug report, sample file, etc. -- surely you jest. I paid 240 euros for the thing and I expect it to work. Otherwise they can offer to pay ME if they want to hire me to help them find their bugs!
So far my dealings with PB and PBgoods have been fine. I will continue to report (for free!) on how things develop.