I have just done a fresh re-install today, and have dumped a bunch of map files into the maps folder. In the past from memory this was all I needed to do to have them load into the game but I've just booted it up and they're nowhere to be found. Has this been changed? Do I need to do something else to get them to load? Cheers

You haven't by any chance installed the game in the Program Files folder?
If so, I suggest you reinstall somewhere else and try again.

If not, try opening a user made map in the editor, save it and see if that changes anything.