I confirm the problems with Vray for Sketchup on a Mac. So unstable, it's unusable. (Latest Sketchup and latest Vray.)
Also, after this trial, I'm completely disenchanted with the Vray material editor. C'mon guys, get real. Sure, it's nice to have N-dimensional complexity under the hood if you need to go in and tweak. But there should be a simple first layer interface with just a few sliders, a la Podium. Oh, and also a bunch of basic materials with the install so that you don't have to go off hunting for something to start with -- especially given your byzantine interface!
This has been a complete waste of time and headaches. I've heard that Podium actually works, so that's where I'm off to next.