I just lost my firefox (1.06) bookmarks toolbar folder and my urlbar has vanished also.
The only thing that helped after a delete and program re-install (and older firefoz versions), find net info, checking view/bookmarks folder and systemrecovery turned out to be deleting the firefoxfolders in the programs dir. and in the settings/application dir. and reinstall.
Took me an hour and a half before I got to that point.
