general problems of the 2000 Oldsmobile Silhouette

My vehicle is a 2000 Oldsmobile Silhouette, VIN #1ghdx03e9yd165077. The incidence happened at 8:15 am, 04/25/2004, at the traffic light at coit road and west 15th street intersection, city of plano, texas. I was heading south on coit road. After on and off thunderstorms since Thursday night, 4/22/2004, it was drizzling and the road surface was wet. I stopped at the traffic light because it was red. I was the first vehicle. Suddenly, the engine speed went up and the vehicle started to move while my right foot was still on the brake pedal. I had to use all my body weight to press on the brake hard to stop the vehicle from moving ahead. The whole ordeal lasted about 5 to 7 seconds. We have this vehicle for 4 years and never have any problem. It is a reliable vehicle as far as we know. This incidence really shakes us up. If I could not stopped the Silhouette today, I would be broadsided, with my children and wife in the minivan, by vehicles traveling from east to west on 15th street. Now, we arent sure if this is one time incidence or this vehicle is a time bomb.