Hey guys,
Sorry it took me so long to reply, I was aways the last days.
So, I ran the checker and I get many errors related to fonts, which do not seem to be a problem when using the Kobo but nothing about the ToC.
I have uploaded the book here, it's the complete Sherlock Holmes series, it is public domain.
https://mega.co.nz/#F!G1sxWZbQ!AQGoNWpYg9VVPz1neziWCg