Gtk-WARNING on steam client

[Stanley]

Just updated the steam client, and got a lot of warning when lauching it on a terminal :

(steam:3139): Gtk-WARNING **: A floating object was finalized. This means that someone
called g_object_unref() on an object that had only a floating
reference; the initial floating reference is not owned by anyone
and must be removed with g_object_ref_sink().

Always same message once per second.

[Stanley]

Update : warning only appears when Steam is downloading materials (TF2 actually). When downloading is finnished, no more spam.

[SPACE_CADET_3D]

I have the same error message.