I have the same issue with Ubuntu 12.04 LTS 64 bit on a MacBook Pro 8,1 (late 2011). Whenever I have Thunderbird open, my CPU usage shoots up to about 20%, my laptop heats up and my battery gets drained atleast twice or even thrice as quickly. Makes Thunderbird unusable on my laptop.
I have the same issue with Ubuntu 12.04 LTS 64 bit on a MacBook Pro 8,1 (late 2011). Whenever I have Thunderbird open, my CPU usage shoots up to about 20%, my laptop heats up and my battery gets drained atleast twice or even thrice as quickly. Makes Thunderbird unusable on my laptop.