Thanks very much. I'd not thought of the websites being different but think you could be right. I'll write to Ancestry.
I have the app on a Nexus 7 tablet and want to put my in-progress tree on it so that I can work when not at home. It only opens when I click on it so is no problem usually but, when I do open it, the wretched Birkenshaw/Blamey/Young tree is there, all over the opening page. It's not so obvious on the PC computer and I've been able to ignore it for years !
Many thanks to all; even if I've not solved the problem at least I'm, not left thinking that it is just me missing something !