Comment 4 for bug 931555

I spent an hour or so looking at this, and I can confirm that the problem lies in the notification area's attempt to get a workview view of the task tree before the tree has been loaded by the backend. I can reliably avoid the bug if I put a return statement just before these lines in notification_area.py:

        return
        self.__tree.apply_filter('workview')
        self.__tree.refresh_all()

I don't know very much about the gtg internals, but my guess is that there's some threading issues in liblarch related to multiple views manipulating a rapidly changing tree. The real fix would be to fix that bug.

As a stopgap, removing the threading from task loading also fixes the problem, and isn't noticeably slower on a large (~150 active tasks, many, many more deactivated tasks) backend. Slower backends would almost certainly suffer, but it's reasonable to expect slower startup times with slower backends, and until the tasks are loaded, you can't do anything with gtg anyway.