Every render layer other than the default renders completely blank/transparent in a Blender 2.62 test scene. Changing the render mode from GPU/CUDA to CPU fixes this.

GeForce GTX 580
Core i7 Westmere

As for the render layers "test scene", a cube on layer one, a large plane intersecting the cube on layer 11, each with thier own render layer. simple enough :D
Each layer renders fine in CPU compute mode, but the layer 11 plane wouldn't render in GPU mode, only the cube.