do you have any extensions installed? If so, please try if running tbird in safe-mode makes this problem disappear:
# mozilla-thunderbird -safe-mode ** Tags added: mt-needsummary mt-needtestcase mt-needtester ** Tags removed: mt-needinfo -- Thunderbird deadlock https://launchpad.net/bugs/71951 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
