Noticed something about the Opal poles on the stations - the pole itself must be manually programmed with it's location. One of the poles on my local station now thinks it's one station further down the line that it really is. So 'randomly' (depending on which reader of 4 you use at the time) you get tapped on/off at the wrong station.
In my case it doesn't matter as the fare is the same either way, but other people may have gotten overcharged and unless they keep checking their Opal history like I do, they would never notice.
I never expected a fixed pole to have a 'geolocation' error.
I had sort of expected the poles to auto-configure off the station controller, but if they did, this sort of mistake couldn't happen.