On Apr 8, 2012, at 12:18 PM, Jeff Cen wrote: > Hi, > > I found my LCD screen brightness increase when I use firefox and other white background editors and screen brightness decrease when I use dark background applications, such as terminals with black background . The change in screen brightness depending on the applications has been annoying. > > > My centos version is ver 5.7 64 bit. Has anyone seen a similar problem or have a solution for that? Thanks in advance. > > Jeff Jeff, Does your machine have an ambient light sensor? Light from the monitor, reflecting off of you, will often trigger changes in the amount of light the ambient light sensor is seeing. Happens most with large changes like switching from a bright white (browser) background to a dark one, just as you describe in your symptoms. Nate