Before zipping this up I thought I'd attempt to replicate on my second workstation. The scene rendered successfully twice before the same type of crash. I've not been working here long, and they haven't used Railclone before, hence I'm the only user. This never used to happen prior to coming here, though I used Railclone 2.4.7 with Mental Ray.
I've worked on only two scenes in the last few weeks, both using Railclone for modelling, and the same issues have occurred in both these scenes. As I'm modelling Railclone geometry, I add a few lights, a camera etc, go to do a quick render with Vray, all fine, then a second render, and crash!
Zipped files will be on there way to you shortly,