Cruise Control problems of the 2002 Subaru Forester

We purchased this low-mileage vehicle (~11k miles) 2nd hand from local Subaru dealer mid-Feb 2006, & noticed only rough shifting when engine is cold- no other problems. Today, while turning left at low speed, the car suddenly accelerated, & seemed to do so for a short time after braking harder. I assumed I had inadvertently stepped on the gas & brake at the same time, & resolved to be more careful. After turning the car off & restarting, I turned right at low speed. As I rounded the corner (maybe as the wheel turned back to the left??), the vehicle again accelerated, continuing to rev as I stood on the brake. The car stopped after striking the bumper of the truck in front of me. Low-speed impact, no air bag deployment, no observable damage to either vehicle. Before I moved my feet, I looked down: my foot was not on the gas pedal. As the gas pedal is somewhat recessed, it would be quite difficult to hit it while braking. Cruise control had been on earlier in the day, but is supposed to shut off when the car is turned off, & so should have been off during both of these incidents. Afterward, I did not look at the cruise control to verify that it was off. The dealer will look at this in 2 days.