I had the same issue on Asus n56v with Ubuntu 13.04. Update to linux-image-3.8.0-20-generic and linux-image-extra-3.8.0-20-generic solved the problem.
I had the same issue on Asus n56v with Ubuntu 13.04. Update to linux-image- 3.8.0-20- generic and linux-image- extra-3. 8.0-20- generic solved the problem.