Yep, this is annoying – iBA seems to have no method for searching and replacing fonts. Not sure there's a workaround. My advice would be to report it as a feature request here:
...and cross your fingers and wait.
Sorry I couln't be more help...
I can't give a conclusive answer on that I'm afraid - so far I've only been in the production side of the process, the publishing section is dealt with by our clients.
I'll email them and see if there was anything that occurred when trying to publish, and I'll post back here if I get a useful response.
You may be able to call Apple support and ask them directly. Is your country in the following group?
Global Phone Support
We have expanded English-language publisher phone support. To make contacting the iBookstore support even easier, new local phone numbers are now available for Australia, France, Germany, Italy, Netherlands, Spain, and the U.K. Support is available Monday to Friday, from 7 a.m. to 5 p.m. (PT).
Country Phone Number Australia 1300 307 504
Note that this is a low tariff number.
France 0805 540 117 Germany 0800 664 5307 Italy 800 915 902 Netherlands 0800 0201 578 Spain 900 812 687 U.K. 0800 975 0615 U.S. +1 (877) 206-2092
Toll-free from U.S. and Canada.
Thank you for phone numbers. I'm in Hungary so there is no online/phone support for us yet.
Tried to check the book with iTunesProducer but it was unable to repair the EPUB.
BTW I have deleted everything (text, images, layout) from the book and I made the sample.iba.
If I open this "empty" file I receive still the
iBooks Author Document warning: The font "Baskerwille-SemiBold" was substituted for the missing font Baskerwille".
Thank you! Yes, if I take on the Baskerville font (regular) with Font Book, then there is no warning.
If I take it off, the Document warning is showed again. So Baskerwille font is in the book somewhere, but I can't localize where it is. I didn't want to use this font, and the warning still exist even if I delete all text, image, graphics from the book.