Using iGoogle - my bookmarks toolbar has disappeared

I've just installed a Firefox update - following this I logged onto iGoogle in the normal way and found that my bookmarks toolbar has vanished. The bookmarks are still there in the library section but I can't get the bookmarks toolbar to show. I've tried right clicking on an empty part of the tab bar - this shows the bookmarks toolbar is ticked already. How can I restore my bookmarks toolbar please. It's a vital part of my browsing.