Sorry, your are correct. It is using the pwm side of the board.
Servo works fine in any initialized pin until the SR04 sensor is hooked up, then it gets jittery when the SR04 is making readings beyond say 25cm, at which time the readings become, around 1/10 erroneous. At 175 cm, the readings are even less stable, and the servo becomes even more jittery.
I may hook an oscilloscope up to the line and see if the frequency to the servo is becoming unstable when the ultrasonic sensor is hooked up. I don't think its the power supply, since I put the servo on its own power supply. I can also try a different SR04, just in case this one is defective.