I've got a Garmin 196, and there have been a couple of times when I've been a bit suspicious of it. Once I had it on when flying between Shoreham and Biggin, although I wasn't using it to navigate, I was tracking VORs and looking out the window. When I checked my route on it later it showed me clipping the corner of Gatwicks airspace.
Now I know most of you are probably going to think that I did, and in some circumstances I might agree with you, but I fly around the area a lot and I'm paranoid about Gatwick, and know exactly where it is, so I'm 100% positive I was a good few miles away from where it showed me.
Having said that, I've zoomed in to an airport and it's shown me right on the centreline of the runway - and obviously that's where I always land
