came back from vacation powered up pc started firefox and pulled down bookmarks. No Bookmarks and would not bookmark new items. I went to safe mode as suggested and re set tool bar. Turned off firefox in task manager. tried to import bookmarks copied from other PC still no go. Totally uninstalled firefox and re installed latest version 3.6.8 still no bookmarks or bookmark saving. What next? runing same programs and protection on 2 PC's. only this one has the problem.