Ok, thanks for the very quick answer. We are animating kitchen appliances and need to hide / show like 50 glasses or water tanks/volumes throughout the clips. We are surprised of this bug/feature because on other renderers visibility 0 means all of the object (surface/volume/shadows/gi contribution) is not visible.
Of cause I'm fully aware animating object visibility is most of the time a bad idea with raytracers which leads to all sorts of funny light/gi artefacts and especially severe performance impacts if all layers and faces of an object needs to be rendered in front of each other, but as least animatioms from 100% to 0% visibility in one frame works fine. If 0% visibility really IS 0% visibility. ;-)