I just realised that version 3 of MOBI header does not support meta information such as author name so the files generated from html or from a PalmDOC file will not have working author information. mobi2mobi will work with adding author information for MobiPocket files.
The annoying thing is that my code for generating version 4 seems to work on all devices except the Cybook. What I get is a message "Multi-part book not supported". So do anybody know what a multi-part book is and if I can find such books to download anywhere or if I can create them using MobiCreator? I have stared at the hex dumps but I really do not see any good candidates for where this information is encoded.