Ghost in the machine?

Weird. I woke up this morning to find that Firefox had developed a mind of its own. (Open the pod bay door, Hal!)

Everything was fine last night, as I took a few notes on Lost, watched the abominable finale of Life on Mars and went to bed. However, this morning, my browser had mysteriously restarted, leaving me with a plethora of tabs telling me that my various add-ons and extensions had been "installed." (of course, all these items have been installed for some time now. And this wasn't the usual "update" that takes place from time to time). Some settings, like bookmarks, FoxyTunes and No Squint, remained exactly as I had them previously. Other settings, like the items on and arrangement of my Firefox toolbar, Autofill information and Tabmix Plus options, were completely changed and restored to the defaults. Even my "home page" settings had vanished.

Not what you want to see before the first cup of java has brewed.

I searched through the Norton logs to see if there was some mysterious virus or intrusion, but everything checked out A-OK. I put everything back in place, because I'm OCD and can't live with that kind of organizational anarchy, but I still wonder WTF happened.