TOC added by calibre is cut short

Hi,

I'm using calibre to convert HTML to mobi.

The original TOC coming from Word (showing at the beginning of the mobi file) is showing complete.

However the TOC added by calibre (at the end, by default), is cut short, missing several chapters at the end.

I would like to use the one from Word, however, it's not seen by Kindle (that is, going to TOC is impossible from the Kindle menu, if I leave just that TOC in place).

I checked the headers in Word, they seem the same throughout.

Any suggestions?

Thanks.