You can opena ticket at
http://calibre.kovidgoyal.net/newticket
@ ==X==
calibre gets the TOC from the OPF file (part of the lit file). If the lit file doesn't have an OPF file, or the OPF file is missing a TOC section, then it wont automatically create a TOC. You have to use one of the chapter detection options to tell calibre how to figure out what should go into the TOC from the HTML