So, cameras seem to become "uneditable" if you make more than 2 and left click one. It seems random as to when or if this happens, but I can assure you it has happened to me. Not sure if this was reported or not. Not a huge problem, but sometime it makes modifying camera parameters a pain. Reloading the level does not help, for the most part. It does allow you to add new cameras, as sometimes the bug does not allow you to.