I witnessed exactly the same behaviour. Mid November I changed some positioning data, because it varied to the actual position.
As I have waited a few days and the change only seemed to be visible in the web view, I searched the forum for any further information. I stepped across the same article as maartenc mentioned and thought the changes would be replicated by January.
However, this is not the case and I hope someone on this forum would be so kind to provide a solution on how to improve/extend the existing data set, not only in the web GUI, but most importantly on the API itself!