For an ePub2, what do you show in the <guide> section of the .opf file? To designate an open page, you should see something similar to the following:
Code:
<reference type="text" title="Startup Page" href="section0001.xhtml"></reference>
For an ePub3 file, the start location is in the landmarks nav section of the navigation document. It would look similar to the following:
Code:
<li><a epub:type="bodymatter" href="section0001.xhtml">Start of Content</a></li>
You can check the following pages for more information:
Adding a <guide> to your OPF file
Adding landmarks to your EPUB 3 Nav Document
Two notes is that quite a few renderers do not support these options and will disregard them and that almost all renderers will only use this start page when the ebook is opened as a new file or re-opened as a finished file.