I use ancestry on my ipod. Here are some thoughts which you may have already thought of. Uninstall re-install on the iPad. It is more of a direct read than the computer sync. Refresh browser on the computer. Sign out and back in to ancestry. Make sure working on same tree. Make change online in ancestry.uk and make sure it shows in other ancestry and iPad. You do have same user name for both??
Anyway you probably already thought of all these but just in case you hadn't.