we've been made aware of a few people having issues such as this and are currently investigating. We are having problems reproducing the problem, it seems to consistently happen for a few customers and not at all for others. It doesn't happen on any of the test setups that we prepared, so any information that we can get about your particular configuration will help us nailing this down. Therefore it would be awesome, if you could contact us directly at firstname.lastname@example.org and provide us with configuration details (Windows version, 3ds Max version, V-Ray version, Laubwerk Plugin version) of at least the workstation and one client that isn't working. An (as simple as possible) test scene that definitely exhibits this problem would also be excellent. Even when that scene runs smoothly here, we definitely know it fails on your side and we can work on coming up with a configuration that lets us reproduce the problem.
BTW: This only happens with V-Ray DR, so if you need to render an animation you can temporariliy resort to using backburner only. This will work.
Sorry for the inconvenience!