Here's my latest endeavor, and subsequent failures.
1. Edited EPUB in Sigil, added the EPUB to Calbre, then converted to MOBI: failure.
2. Converted failed MOBI back to EPUB, edited titlepage.XHTML in SIgil, then sent back to Calibre, removed the old version and added the new verion, converted to MOBI.
What conversion software would you recommend for a Mac user?