I think this is a problem....

[vlado]

Multi/sub materials are not a problem.

The standalone version of VRay can blend multiple shaders efficiently with respect to lighting, but that's a different story...

Best regards,
Vlado

[dbuchhofer]

Careful with that 'S' word vlado!

Good to know the about the blend material..

[rhino]

Finalrender behaves exactly the same too when using blend with refractive materials

[Morbid Angel]

yeah its a max limitation. Im gon do some tests in maya to see if it works any differently...if so then I will request autodesk in next release to fix this.