If an addon "installs" properly or not, that doesn't mean much, whether that addon really "works" or not.
It merely means that the min-max version numbers which the addon author wrote manually inside the install.rdf file, are matching your current browser version. It does *not* mean the browser were automatically executing any feature compatibility tests before allowing installation.
For trying Firefox addons in the earlier KM7x versions we had to manually edit and fake those numbers all the time, to allow installation, and then just look and see if it works or not, or partly.
Since you realized already that an addon is causing your prob, disable half of them, restart and check again.
If your bookmarks and history are blocked, that could point to a privacy related addon...
It can also happen that two addons are just conflicting with each other.
And, although forbidden by Mozilla, it happened in the past that an addon author (Maono, of NoScript) intentionally manipulated another addon somehow (ABP, from W.Palant), so that his own stuff wouldn't be blocked.
It's probably rather easy for addons to manipulate other addons intentionally.