Comment 8 for bug 211264

I can confirm this, happens usually (not always) if you close liferea when it's updating the feed list and the 'feed update notification bubble' is visible on the screen. My backtrace is identical, using liferea 1.4.14-0ubuntu3 and xulrunner 1.9~b5+nobinonly-0ubuntu1.

apport doesn't notify about the crash, but stale lock file is left in ~/.liferea_1.4/mozilla/liferea/ directory.