I would not say broken, but...
Since said HTML book does not contain pagebreak information
it has to be rendered in one big / long / however you call it page...
Read such - but not so big - book once. Having just one page I had
to scroll every time I stopped reading back to the line I read last.
Not too bad in the beginning, but towards the end of the book
quite unnerving...
Converting your book to PDF will bring you pages and the IPDF viewer
has the capability to remember your last page read.
Dirk