you should consult apple's ibooks asset guide to see if there's an easy way of resolving the issue with the spreads.
otherwise, i think you'll have to split each background image in half, and treat each HTML page as one half of the spread.
so, instead of
Code:
+---------------++---------------+
+ + +
+ + +
+ + +
+ page1.xhtml +
+ + +
+ + +
+ + +
+ + +
+---------------++---------------+
it should be laid out like
Code:
+---------------++---------------+
+ + +
+ + +
+ + +
+ page1.xhtml + page2.xhtml +
+ + +
+ + +
+ + +
+ + +
+---------------++---------------+
at that point i believe there would also be a way of addressing the autoplay depending on which page is being viewed.
hope that helps, and post back if you do find a quick-fix.
incidentally, some of your (apple proprietary) markup is a bit outdated. you should be using
Code:
<meta property="rendition:orientation">auto</meta>
<meta property="rendition:layout">pre-paginated</meta>
...
in the opf instead of using options tags in the ibooks.display.options.etc..
also don't forget to include a landmarks section in your toc.xhtml. it's a common error that sets you back while uploading.
good luck!