1997 Chevy Camaro intermitent loss of power

Sometimes the car will hit a bump in the road which causes the radio, clock, power windows and power top to loose power. Sometimes when the car is first started it will not have power to these components. It will usually return power when another bump is hit. You cannot make this happen, it does this at random times. Battery is clean and new, circuit breaker in the passenger compartment has been replaced. This is a one owner car that has been taken care of, never raced or rodded.