The Ubuntu 11 Firefox 11 distro will come bundled with a couple of toolbar integration extensions for Unity. The active toolbar will either say Firefox or Library, once you move the mouse pointer to it the option for exporting bookmarks etc will appear.

Attempting to add some kb screenshots did cross my mind but i am not sure what was decided about whether these extensions had to be disabled. I have attached screenshot here though

Thank you for your quick reply. All my focus was on the library windows since the main menu of firefox is hided by default in Ubuntu Unity. Now i see it and i succesfully restored my bokmarks from my json file. Thanks again :)