I don’t know which one is responsible, but I installed Chrome last night, and then updated my Firefox browser this morning — and all of the Firefox bookmarks, passwords and history are now gone.
Completely and totally kaput.
I am not sure which one gets the blame, but I would be cautious with these two — they don’t seem to play well together.
UPDATE: Looks like it was a Firefox issue . . . I found the back up data (Thanks, Matt) and am back up and running. (I don’t know if Chrome had anything to do with this)