No not yet, You can change the color of the light, but even pure black does not seem to take it out completely.
Try bringing the ambient completely down and see if that gets it.
If this is an inside scene, I have put walls around my stuff that completely block the skybox light. Not to bad, but not the best.
Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz, 2400 Mhz, 4 Core(s), 4 Logical Processor(s), 8gb RAM, Nvidia gtx660, Windows 7 Pro 64bit
