Standard Servo Command A Little Off?

I've only tested a couple of my standard parallax servos but both are showing the same inaccuracies. 0 degree command seems ok. 90 degree command is 3 degrees off (ie 93 instead of 90). 180 degree command is 7 degrees off (ie 187 instead of 180). Actually the 180 degree command hits the hard stop on the servo.

Anyone else seeing this behavior on their standard servos?