I have experienced 2-3 unexplained lockup over last 10 days.
Today, I had a random lockup (no mouse, keyboard response, 100% CPU). But, when I finally switched (Ctrl-Alt-F1) to command line (it took several minutes) it told me that thunderbird-bin had locked a CPU.
I ran this to resolve:
pidof thunderbird-bin
sudo kill ####
However, after saving other work, I tried restarting Thunderbird. It went to 90%+ CPU, and within 20 seconds it locked again.
Once I have more detail I will raise a bug (on Ubuntu Forums).
Does anyone have any other suggestions, advice?
UPDATE: (Sep-2012)
Thunderbird 13.0.1 is quite stable in safe mode. Still working to resolve ..
UPDATE 2: (Jan-2013)
Now running Thunderbird 17.0.2 (Ubuntu 12.04).
Still have ALL Plugins disabled. Works well, and does everything I need.
Not attempting to resolve.
Best Answer
Change the configuration key
to
In Preferences->Advanced->General->Config-editor
Source: http://rainbow.chard.org/2013/02/19/thunderbird-high-cpu/