I had problems like this until I isolated my servo wires. I'm using a PC power supply and noticed that I would get issues like this if anything else (fans, lights, anything) were plugged into the power supply. Then I made a little board where I placed a .01uF ceramic capacitor between the signal line and ground, as well as a 4.70uF electrolytic capacitor between the 5v and ground. My jitters and inconsistent servo control went away. Perfect deployment every time, and I can keep anything I want plugged into the power supply, so I have lights and a fan there also. You might check into something similar if you havent.
Edit: Oh, and if you've extended the wires for the servo like I did, I put my little board right at the end of the original servo wires.
Edited 2 time(s). Last edit at 12/31/2014 05:00PM by FA-MAS.