Windows 10 64 bits, Nvidia GTX 670
Broken: Blender 2.77 RC 1 b594b25
Short description of error
Point light not working properly inside a volume while using GPU. It lightens the material, but not interacts with the volume. With CPU rendering, it works fine.
Exact steps for others to reproduce the error
Place a point light inside a volume, with another mesh to lighten.
The light in the example comes from HDRI environment map and from point light.Blend file with the problem
CPU viewport, working fine
GPU viewport, not working properly