First I'll say that I'm no car expert but I know a little bit...
My ABS light in my 94 Supreme would come on all the time but it wouldn't affect the brakes. The car was taken to a mechanic and the problem was solved. I don't exactly know what was wrong...Last year around this time, my brakes were acting up and sliding before stopping, which kind of scared me. After a couple weeks of the brakes acting like that, my Brake Light and my ABS light on the dash would come on when the car started. Of course I read the manual and it said not to drive the car when these lights came on. After these lights came on, my brakes worked perfectly fine. I never got it fixed because I don't drive that car anymore...The moral of the story is...Don't always listen to the manual :-)