Strange (power?) problem with Arduino Uno/Tinkerkit shield

Using Arduino Uno and Tinkerkit Shield:
I made a very simple script:

  • reading the value of a potentiometer
  • driving a servo motor based on this value
  • fading a LED based on this value
    The LED doesn’t fade, but stays low till value 1019 and goes high on 1020.
    However, if I put the servomotor instruction in comments (to test the LED part of the program), the LED fades as expected…
    Apparently the board malfunctions, once I activate the "TKMicroServo.attach(O0) " instruction.
    Does this mean the Arduino with Tinkerkit shield has not enough power to drive 1 servo + 1 LED ?
    Or is there another problem?

/*
Read value TK Pot I0,
Drive TK MicroServo O0
Fade TK LED 02
*/

#include <TinkerKit.h>
#include <Servo.h>

TKPotentiometer pot(I0);
TKLed led(O2);
Servo TKMicroServo ;
int waardePot = 0 ;
int hoek = 0 ;

void setup() {
TKMicroServo.attach(O0) ;
}

void loop() {
waardePot = pot.read() ;
led.brightness(waardePot) ;
hoek = map(waardePot, 0, 1023, 0, 179) ;
TKMicroServo.write(hoek) ;
delay(10);
}