Our team is using omni/mecanum wheels this year as well. I was just thinking, we had this same error and all too with our servos, and I think it might have something to do with not defining slots on any of the others.
such as
Code:
// see driver station dashboard for module numbers
Gyro gyro = new Gyro(1); // Gyro in PWM channel 1
Servo servo = new Servo(4,1); // Servo in Digital IO channel 1
Do you think it might have to be
Code:
Gyro gyro = new Gyro(1,1);
Servo servo = new Servo(4,1);
for it to work correctly?
All just complete guessing, I'm kind of hopeless right now, it seems the robot just doesn't want to cooperate this month.

If anyone finds the real answer, please share!
Thanks.