I have a new Samsung RV520 and have just installed Precise Pangolin 12.04 LTS. I am having serious problems now with the wifi constantly disconnecting. This then causes the brightness control to appear on the screen. The screen starts flickering and then freezes the whole machine. Indeed the brightness control doesn't work at all. I am using a Intel Centrino N wireless card. Please can anyone provide any guidance as to how to resolve these issue on this machine. Many thanks for your help.