What do you have for tires? The stock Michelin's suck, even though they are V-rated (speeds to 149mph). Although I must say I never had any experiences of the car getting squirrely under high speed braking.

RSXxXMeg82
Check the torque on the lugs if you think your rotors are warped, shouldn't be higher than 80 lb-ft. Most places that put wheels on cars just use the torque sticks, and may over tighten.