The package latte-dock requires plasma-pa and pulseaudio-module-gconf, and sadly I can't install these packages because somehow they break my pulseaudio, so I can't install latte dock, too.
I spoke on reddit to the mantainer of Latte, he told me these packages are not needed by Latte Dock in any way, so I decided to bring the matter to your attention, as it could just be a mistake on the list of the dependencies.
Regards.