I've had my pv2 for a couple of weeks. After upgrading the firmware switching to FCC mode and switching out the props there is a noticeable difference in the yaw drift. I've had a couple hard landings as well. The phantom still hovers nicely with little or no movement. When I yaw CW or CCW the phantom drifts 10 to 15 feet from its position. Then slowly moves back to it's starting position. (Assume that's the gps mode working) I didn't notice any drift before the transmitter calibration and firmware upgrade. I've tried adjusting the yaw gain via the assistant software up to 150 and down to 100 and all the 10% increments in between from the default 120. No setting in that range seems to make any difference. Is it possible the new firmware has different default config values that would have negatively yaw drift? Do the gain settings even affect this? I found a pic explaining what my phantom does that the problem. I assume this is yaw drift? Only difference is I don't see a significant altitude change and after it moves back to starting position. I'd really appreciate any help.