Just a minor bump on day one back in July which never caused any problems (travelling very slowly and landed on its side when I brought her in to land) at the time and I went as far as to put new props on it just to be safe. I also checked inside for any loose solders, anything else untoward, etc, etc.... As for the calibration "dance" - absolutely no metal structures within the local area, just a green field..... Also tried it in my garden far away from the house and got the same result.
I tried the advanced calibration this morning and it is maybe ever so slightly better but still get the drift..... This is particularly a problem if I want to go up vertically and by the time I am at say 200 feet the Phantom 2 has drifted 10m or so either direction laterally, and this is on a calm day - and worse in the wind I think? I am looking at it and it struggles to maintain the same altitude - the variation is much more than when I bought it new and also as seen in YouTube videos which show similar setups to my own. I get like a metre variation vertically either way as if it is struggling even on a calm day - it was never like this so I know what normal should be like.
It has the general stuff fitted properly - the Zenmuse H33D, GoPro Hero3+, iOSD Mini, and ImmersionRC 600 with Spironet V2. Nothing out of the ordinary.