how to get it for pages not in menu???

Hi,
I like this plugin very much and I put the header images to all my pages. So, there is a problem, because a lot of pages which are called in some way on this website are not part of the menu. So, there is no header image – and this is destroying my design completely.
I already added some pages in the menu hiding them by css. But there are other pages which I can`t add in that way. EG I’m using events manager, here There’s a lot of subpages which will be called from within this calendar, eg location-list, single location pages, categories list, and a lot more.
Is there a way to add some code somewhere to show the header images independantly of what page I call?
I would also be satisfied with a kind of “if this is any other page than those from the menu -> then show always one special header image”