I’ve started to use google sync, to syncronize my bookmarks between my machines (Desktop XP, Desktop Ubuntu, Notebook, Work XP, Work Vista). When I installed GSync on the new Ubuntu installation it … crapped all over my bookmarks and everything from my “bar”, where I keep the most important things, was gone.
Luckily Firefox keeps series of backups of the bookmarks in a sub-directory below your profile directory. Look for around for c:\documents and settings\yourusername\application data\mozilla\firefox\profile\default.xyz\bookmarkbackups – note that the “Application data” directory is hidden, so you have to have “show hidden files” turned on, in the explorer settings.
Just open the bookmark organizer in Firefox, and import an old file. Find the old “ToolBar” root and select “edit->Set as bookmarks toolbar folder” in the menu.