Bug#862584: It looks thet problem is not in thunderbird, but lookout extesion :(

[Kamil Jońca]

I did some tests, and it looks like, after disabling "Look Out (fix
version)" it works ok.
So my bug is rather invalid.

KJ
-- 
http://stopstopnop.pl/stop_stopnop.pl_o_nas.html
An algorithm must be seen to be believed.
                -- D. E. Knuth