AeroPod, PowerPod and Newton

I tried to calibrate an iAero over the weekend and had some dramas. I went over the same place I have done calibrations on the iBike I and II, did the coast downs on some quite smooth roads but got bad coast after bad coast. I noticed some really high power readings when trying out diffferent section of road and determined the tilt was way off. I did the tilt and wind offsets before I left home (got the good tilt message) and tried it again on the road. Once I did it again I got a good tilt and tried it out but no luck with the coast downs. I did the tilt again and it seemed to work as the coast downs were OK. Then I did the out and back cal ride, again it seemed OK.
Then on the way home the power and tilt readings were very high (I reckon about +3.5% tilt). I checked the mount and it is still rock solid.
I have attached the files, could someone else take a look and advise if it is the unit or anything I am doing?
The post calibration ride is uncorrected. Looking at the slope vs elevation power analysis, the tilt seems to be drifting quite badly.

I can rule out cold weather. It is summer here in Melbourne. It was mid 20'sC (77degF) during the calibrations, and just for information, the next few days will be low 40's (106degF). It's the kind of heat that dries out your eyeballs and I think by the weekend I will be wishing I was someplace where I would have to worry about battery life and cold weather!

John at Velcomp has had a look and will replace the unit. Thats service.

Further to my last, I rode home from work this afternoon and it was 43degC. It was so hot the patches on my inner tubes gave way.

OUCH!