I'm making some test to understand this problem... and i've find another strange thing... I've load my scene (animated): now i want to make a test rendering to view the result. I've tried to render all the animation only with my workstation and the result is 35 min. (low res mode) After this i've launch rendercow on my workstation and i've restart rendering but i've select the netwok render and i've add only my workstation as node: the render time (same scene and seme setting) go to 1 hour !!! So rendercow slow down.