Originally Posted by Hitch
AFAIK, your problem is that you don't know, because you're not working in CV (code view) where you are actually inserting the image, and the page-break. If you've inserted the cover INSIDE the header tags, yeah, when you "break" that page, the cover will suck that header right along with it, because they're all (break, cover, header) in the same paragraph. Sigil is doing what it should.
Just turn on CV so you can see what you're doing. Then it's simple. No reason for sturm und drang; if you work in BV, it's like working in bloody Word--you can't see what you're doing, so of course stuff will get bollixed up.
My point is more the official tutorial will cause a significant issue. That means either the tutorial is wrong, or there is a bug.
I spent hours trying to figure out what was happening, and there has already been a post since mine where someone else ran into the same problem following the tutorial. I don't know who has access to edit the tutorial, but someone really should... OR, this is a bug, and it should be fixed. Either works for me.
I realize there are always going to be issues to some degree, but having a simple procedure like adding a cover break an epub if you follow a simple tutorial seems a bit much to me.
As a side note, while you're correct that working in code mode is superior to wysiwg mode for the reasons you discuss, that pretty much defeats one of the major goals of sigil -- to allow you to edit epub files in a wysiwyg friendly manner.