GPS glitch found in logs

Hi,

I have the following setup:
S500 quadcopter frame
Pixhawklite flight controller
Turnigy 2830 1000 kv motors
Afro 30 amp ESCs
NEO-6m GPS with built in external compass.
Firmware version: 3.2.1

I had the above electronic components in an X525 frame and it flew fine. Then I moved all components to the S500 frame. In the maiden, mission planner showed “No GPS”. I found that one of the GPS wires coming in to the board was loose. Went home, fixed the problem, and then tried again the following week. Everything seemed fine at start up, mission planner showed “3D Fix”. I took off and switched to loiter, seemed fine but not as locked in as before. Pushed the elevator stick forward and the quadcopter moved forward but not smooth and showed hesitation in forward flight. when I released the stick, the copter moved back and forth.

The logs show several GPS glitch messages although the number of satellites was 12 most of the time and HDOP was between 0.7 & 0.8 which I thought was unusual because in the previous frame it was averaging 2.0.

I checked all GPS connections and they seem fine. What is wrong with my GPS?