We went to the airfield so I could play with the compass on the plane - I've come to the conclusion that the problem isn't so much the environment it lives in as it is the angle of the instrument panel - I did some reading, and at around 18 degrees, it'll stop working. Well, I think the panel's pretty close to that. I have a couple of compasses now, so I zip tied them in interesting places and went out to test them :o) After spending about 20 minutes getting them all roughly adjusted, and taxying up and down as the flying monkeys kept changing the runway they were using, I threw in a couple of circuits. They panel compass seems OK.
In the evening, we went to the EAA Christmas party, where Danny and friends provided the entertainment.