Hey !
OKay, odd things going on. I couldn’t get the glass object I’m working on to look right,so I made a simple test scene. One room, inverted box, one glass object box, everything tripled, just to be sure. Four point lights with falloff, no radiosity.
Here are the results:
Glass without nodes
Glass with dielectric node material
What’s going on ? Look at those strange triangular artifacts ! Rendered in 9.3 and 9.5, same result. FPrime renders it correctly. Also turning double sided on makes the artifacts disappear, but obviously you get completely different results…
If anyone could look have a look at this simple scene and post his findings, I would be forever grateful 
Download Scene
