I was looking at the servo product page:
https://www.servocity.com/html/hs-78...l#.UzfFvvldV8E
(the standard KOP one is this one)
http://www.servocity.com/html/hs-311...l#.UzfF4PldV8E
and I noticed that it says it only rotates clockwise. I'm not sure if that means that it needs to be manually reset, or if that means that if you try to set it back to 0 it will keep going until it's encoder reads back 0. one thing you may try to do is (if you have one) use an arduino and just test the basic functionality of the servo on that. the arduino IDE comes with example servo programs that should work and give you more of an idea if your programming is wrong or it is just a very abnormal servo.