Trawling around my tree I can see that this problem applies to MOST profiles but not all. If I delete the data the problem re-emerges in the next box down but the altered box is OK. Some affected profiles I haven't looked at for many months so it isn't anything to do with settings on individual pages.
I don't really want to provide a link because the way I see it that would give access to my entire tree.
I am afraid I am not much of a techie and don't really understand about Add-ons. However I can say that this problem has only been around for the last couple of days and I haven't received any updates to Java and the like. I do know that IE9 is up to date because I had Microsoft updates recently. I doubt if this is a problem with my settings.
Perhaps I should phone Ancestry tech support.
Thanks for all your input, it is appreciated.