I am baffled at to why the following code won't run as it should.

nSyncedMotors = synchBC; //Synch motors B & C, B is the master
nSyncedTurnRatio = 100; //the wheels will be 100% synched
motor[motorB] = 50; //the robot’s power level is 50%
wait1Msec(5000); //the robot will move for five seconds


What is happening is that the robot is turning in a circle instead of moving straight ahead. I have tried turning off PID and then turning it back on. I have reloaded the firmware. I have checked connections between the brick and the motors. All of these things don't have any affect on the robot.

Thank for your help.