Backface normals showing in Vray, front of normals invisible

I’m working on some Vray materials and I brought in a .dae of a sink I’ve been using for other projects. When I bring it in and try to view it in Vray, the faces show as invisible as if the normals are reversed, however in the monochrome view you can see that they’re not.

I then reversed my normals (so that they are now facing the incorrect way and show up blue) and the sink is rendering correctly.
Has anyone had a similar problem? A friend brought the sink into his sketchup scene and for him it worked fine.

I get the impression it is a problem with the model - can you upload it?

Have you set your front face colour to blue and back faces to white in your style settings?

Sorry, I’m not at the right computer to upload it now, but I’ll get back to you on that. I can tell you though that I brought the model into maya as both an fbx and a dae and there was nothing wrong with it, and the normals faced the right way in there. And like I said a friend brought the same model into his sketchup and it worked fine

No I haven’t changed any of that, and there are other models in the scene with their normals facing the right way (and they also render correctly) and they’re showing as white