cycles GPU renders almost completely dark

In the latest builds (at blender and graphicall), I’m getting gpu renders that are almost totally dark - cpu is fine. Happens with preview and F12 render. I’m wondering if this is a setting I hit by mistake or a bug? Any one else seen this? I’ll post pics if needed, but its pretty obvious…

Works fine on my end, Need more system specs / pictures… gpu? windows/mac/linux? gtx 580/680 etcetc?

Is it possible that you’re trying to use something (like sub surface scattering or volumetrics) that isn’t GPU supported? What your describing is what I’ve heard happens when that situation occurs.

Its an issue with the multiple importance setting for world property and is already logged on the dev site.