Wierd Issue with PWM pin
It is a timer conflict.

The Servo reference says: "...use of the library disables analogWrite() (PWM) functionality on pins 9 and 10..."

This is a picture of the pinmapping of the Arduino Uno: PighiXXX - Uno.
Pin 9 en 10 uses OC1A en OC1B for PWM, that is Timer1. You can't use PWM on them when the Servo is used.
Pin 11 uses OC2A for PWM, which is Timer2.  

I suppose it will work if you choose another PWM pin for analogWrite. Timer0 is used for millis and therefor the PWM frequency will be different (pin 5 and 6). That is mentioned in the analogWrite reference. In most cases that is not a problem.
Pin 3 is a normal PWM pin.

This is a common problem. The documentation is not always clear about the use of timers and other parts of the microcontroller. Many times the source code has to be read to see what is used. In the end, you need more experienced Arduino users to spot the conflict.