It does normally help to keep up-to-date on browser versions. Your Sytem Info is showing version 2 of firefox, so maybe you have already downgraded.

One advantage of recent versions of firefox by the way is that it keeps auto backups of bookmarks, at least for a few days. As you now realise it is also prudent to periodically, export bookmarks and keep them in a separate file.

I can not answer your questions maybe someone else will, I can however point out some articles that may be of interest to you:

• Recover lost or missing Bookmarks
• Firefox 3 upgrade switches bookmarks and other settings to older version

■A usual few words of caution

• - export any bookmarks you have now, and save them somewhere safe
• - and continue to do so as you work on restoring bookmarks (it is very easy to overwrite and loose files / bookmarks )

I can not remember now how & where Firefox v2 stored bookmarks but hope the above articles are of help

Firefox 2.0.0.20 uses the file bookmarks.html to store the bookmarks.
Firefox 3 version store the bookmarks in a SQLite database file places.sqlite.
If there is a file places.sqlite present in the Firefox Profile Folder then Firefox will use that file. To make Firefox import the bookmarks from bookmarks.html you need to delete places.sqlite and all JSON backups in the bookmarkbackups folder.

See also:

• http://kb.mozillazine.org/Lost_bookmarks
• http://kb.mozillazine.org/Backing_up_and_restoring_bookmarks_-_Firefox