Hey. So, I had the newest Nvidia drivers for my GTX660m which was the 327.23. I just redownloaded the most recent one beforethat which was the 325.80 (beta). Under that driver, it still has the same effect. Is that the "previous stable Nvidia driver" that you were talking about? Or were you talking about the most recent one before the newest driver that was not beta? Here is the link I was using for reference:
http://www.nvidia.com/Download/Find.aspx?lang=en-usAlso, some more information I found out. The dimming effect does not seem to occur when the laptop is plugged in to the wall. Thanks.