Docky sometimes starts invisible

[RobinJ]

When I boot up my computer and login, I'd expect to see the gnome panel on top and the docky launcher on the bottom of the screen. Only, sometimes Docky likes to play hide 'n seek. It's there, but inivisible. http://minus.com/mstiPA8Du#1f
When move my cursor over the place where Docky is supposed to be, however, the application name balloon thingies still show up. So Docky is there, but it doesn't show itself. http://minus.com/mstiPA8Du#2f
When I click on the place where an app icon is supposed to be, nothing happens. I've got to kill the dock (killall docky) and start it again (docky) manually. And most of the times, it shows itself again after that. Sometimes I've got to kill it again to get it back.

Elementary OS 0.1 Jupiter
64-bit
Intel Core 2 Duo 2GHz
2GB RAM
NVidia Quadro NVS 110M, no proprietary drivers installed, compiz enabled.

[Robert Dyer (psybers)]

What version of Docky.

[RobinJ (robinj)]

[Info 17:18:28.824] Docky version: 2.1.3 bzr docky r1804 pre-release
[Info 17:18:28.859] Kernel version: 2.6.35.30
[Info 17:18:28.861] CLR version: 2.0.50727.1433

[RobinJ (robinj)]

Also, right-clicking on the invisible dock doesn't seem to trigger any kind of event.