Lightroom 6.0.1: GPU acceleration: Edge and shadow around image are missing

Whith GPU acceleration on, in development module the edge and shadow around the image is missing. For instance, when an image with white background is softproofed, you don't see where the image borders are.

Windows 7, video card info:

GeForce GT 520/PCIe/SSE2

Check OpenGL support: Passed
Vendor: NVIDIA Corporation
Version: 3.3.0 NVIDIA 350.12
Renderer: GeForce GT 520/PCIe/SSE2
LanguageVersion: 3.30 NVIDIA via Cg compiler