[Po Pimp]

I think you may just be a little paranoid on this one. Sounds like some standard issue GM lighting to me, all except the fog light indicator going off. These cars do suffer from fog light problems. They can and will malfuction but it will not take down your lights.

If it is an over cast day (sounds like it in your story) or if you are driving on a road with a lot of trees on the side of the road your lights can and will turn on/off. There is a 3-5 second delay from when your sensor senses the lack of light and when it reacts to it. When the lights come on the instrument cluster lights and the rest of the dash dims. The reason the lights dim is to reduce glare and eye strain in dark situations. With the lights off the instrument panel does not light and the rest is brightened. This is to help you see the read outs in bright situations.

Sounds like your system is working right to me. If you are feeling bored you can clean the sensor. It is located on the top of your dash in the middle of your defrostor vents. It looks like a big black nipple. The only way to properly clean it is with an eraser. These being dirty is not usually an issue unless it is mounted in the grille (on old school automatic high beam set-ups) and the Catera does not have one of them.