I added this to the accordion menu css file
background:url(../images/s5_accordion_menu_back.png) no-repeat top left;
margin:3px 0px 3px 0px;
and now I have the "button" images showing on the pages on which they weren't showing
The expand and collapse behaviour seems odd though.
If I click on a parent menu item I'm taken to the page and the submenu expands (internal link to article).... or I'm taken to the page and ALL the submenus expand ("external link" to url... although its still within the same site and the joomla ap, its just a particular view of a component, so I have to access it via an external url link).
If I click on a submenu item, I'm taken to the page and each time bar one, the menu collapses, which I would not have expected. There is no difference between these menu items other than the article they point to.