If the content is loaded after page “load” event firing, then the back button would not take you back to the position you were. Because the browser scrolls before the ‘load’ event.
To make the browser remember the scroll position in this case, you have to store the scroll position and status (what content have been loaded) somewhere before navigating away. Either in the cookie, or in the url hash.
If pageA is just a static page without dynamic content (loaded after ‘load’ event, the browser should remember the scroll position when you go back.
For dynamic content, there at least includes two parts. One is recovering the page status when click “Back” button, so all the dynamic content is loaded, some expander are expanded or collapsed. The other is scroll to there.
The first part depends on how the page is implemented. The 2nd part you can put the scroll top into the cookie when page doing onUnload. For example
$(window).unload(function() {$.cookie('scrollTop',$(window).scrollTop());});