You can't use PWM on pins 9 and 10 at the same time as the Servo library because they use the same internal timer.
The Servo library supports up to 12 motors on most Arduino boards and 48 on the Arduino Mega. On boards other than the Mega, use of the library disables analogWrite() (PWM) functionality on pins 9 and 10, whether or not there is a Servo on those pins.