Ok, one more test: if you disable all lights and GI and just render with the default light, what do you get (this is to figure out if the problem is really with the shadows, and not the materials)?
Are you talking about the bright areas beneath the plates? We are having this too! We aren’t too far from the origin - only 10m or so in x and y. The lights are standard Max lights with vray area shadows, but they seem to ‘see through’ some of the objects in a similar way.
EDIT: It appears turining the bias to 0.0 sorts things out for us. What is this ‘bias’ all about and why doesn’t it default to 0.0?