I flew the P4P yesterday and had a couple of wierd things, took off flew forwards and when you came to a halt the drone would make a sort of half circle each time, I then noticed there was an error in the sd card, brought the drone back and landed, which was a bit fun because each time you went to hover it would drift in a half circle, I rebooted and then see the sd card showed ok and the drone stopped drifting when flown ?

Sounds like compass isn't calibrated right.  Try a complete recal, and re-format the card too.

I will do that, was under the impression that you should not calibrate unless it was telling you to in the menu ? I did a compass calibration when they fixed the IMU problem

Be sure to take off from non metallic surface.  Concrete has rebar mesh.

Hello Snowwolfwarrior, please test more and if there's any issue, feel free to let me know.

Snowwolfwarrior Posted at 2016-12-22 00:09
I will do that, was under the impression that you should not calibrate unless it was telling you to in the menu ? I did a compass calibration when they fixed the IMU problem

I would try an IMU calibration first, and then another compass calibration. It could be that you might gave gotten a bad compass calibration from the last time you did it. Please try Paulemus's advice as well.

The SD card has no effectr on the flight of the aircraft.