My users are given the wrong real names ...

I'm posting this because it might be helpful to someone who encounters the same problem.

I love masquerade and used it extensively during pre-launch testing without any issues. A few days after going live, I was horrified to find that my own content displayed one of my user's names as the author. When I clicked "edit" the author information still had my correct username there. This occurred on my profile as well. It also happened with some other users I had loaded early in the process, but for the most part the 30,000 or so legacy users' information displayed correctly. I am not sure, if left long enough, whether all user names would have been affected or not. We imported a lot of legacy data and it's possible there may be something in there, or not in there, which was causing this.

I am also using Realname on the site. After turning off Masquerade this error continued to occur, but after uninstalling it and running a php update it has stopped happening. I am not sure if there is a conflict between Masquerade and Realname or if this has resolved it in some other way. Shame, as it was really useful but especially now the testing is done, I can live without it.