Dexter_Morgan - As to whether or not certain things were doctrine (such as geocentrism), in short, they were not, just as our current understanding of physics/biology is not doctrine either. Rather, the Church, when asked about scientific matters, will explain what it believes to be most plausible given the current body of scientific knowledge combined with its understanding of theological truth. This opinion, however, is not doctrinal, but rather the Church's best attempt to answer questions that have been asked.
On the whole council issue, I will agree that there have been disagreements in the past. However, the point I was making is that within the Catholic Church (not any of the other churches), the doctrine has remained consistent throughout its history. Various dissident groups (such as those that reject the Second Vatican Council) do not represent the views of the Church proper, and if you look at the Catholic and Orthodox churches as an example, their doctrine is extremely similar on all but a few technical issues. I can not really say much about the various Protestant groups (because I am not that familiar with them and there are a lot of them), so I will refrain from adding anything on that particular topic.