Hi All,
I was missing some TikZ libraries and so decided to update pgf through MikTeX's Package Browser. I did this by uninstalling pgf and then reinstalling it. When I tried to LateX a file that compiled OK before, I got an error message: The function `add' already exists. Does anyone know what I did that messed things up and what I can do about it? I'm guessing there's a duplicate file around somewhere but have no idea what it is or where to look for it.