Disappearing Bookmark files for no apparent reason, revisited

I am very ashamed that I never replied to the several members who offered suggestions or asked questions similar to mine. I never had to go with the suggestions because the missing files suddenly reappeared, giving support to my feeling at the time that they were still in my hard drive. But, the "fix" happened with no action on my part, save several restarts as a normal routine. I apologize for not getting back till tonight when I saw I had never responded.