Hi, Reinstalling/Updating extensions solves the bookmark problem. I think the culprit was BookmarkTags extension.
However if you have "Clear private data when firefox closes" checked in Preferences -> Privacy -> Settings, firefox closes the main window but does not show the dialog box for clearing the data. Killing firefox with a Ctrl-C or killall is possible. After starting firefox again, you will be presented with the dialog box, clearing the data then launches the main window. Hope this inconsistent behaviour will be fixed. -Rajesh
