Same thing happened to me on my Samsung tablets; my bookmarks went all wonky on the home screen. But now I'm using the latest Firefox from the Google Play Store. The description in the Store says Firefox for Android now has an 'Updated Home design with Top Sites thumbnails'. So I now access my bookmarks from within the browser itself. My bookmarks don't show up on the tablet's home screen anymore; at least I can't see any way to add them to the tablet's home screen. But I prefer it that way, as I don't have the problems with bookmarks when updating Firefox.