[leijoninna]

Thanks :) However, that was one of the first things I tried.

But, after studying the error and all the attributes that the epubcheck expected instead of "prefix", I did find one named "epub:prefix". So epub:prefix="ibooks: http://vocabulary....." did solve the error and there are no more issues in epubcheck.

I did not work anyway with the "ibooks:reader-start-page", it still opens up to the front page. So I guess that is a bit of a lost case.

Thanks for all the help, I will probably have more questions along the way. Great forum!