I must have been lucky with my update.
As far as the missing file in my Bookmarks. Mine contained all my forums. Some of which I only visit a couple of times a year and can never remember their exact titles. Although I had used one of the links in it the previous day the folder had vanished, no trace of it tucked away anywhere and restoring the Bookmarks to an earlier date didn't turn it up.
Tracked it down by using the Bookmarks search option for one of the forums that I knew was listed in the missing folder. Much to my surprise the forum details appeared and my forum folder popped back up in the main list. As I said .. most strange.