[Useless]

Frank, with Firefox open, try Bookmarks > Manage Bookmarks > File > Import...Select 'From File' and search in C: Documents and Settings/Your UserName/Application Data/Mozilla/Firefox/Profiles/whichever profile you use/bookmarkbackups/
and find the most recent file.
If that doesn't work. Take one of those backups and use it to directly overwrite your empty bookmark.html in your profile folder.