After bashing my head against a brick wall last week trying to get ROS to talk to my ar.drone, I decided to use a new(er) computer. Built according to the
http://robohub.org/up-and-flying-with-the-ar-drone-and-ros-getting-started/ page - worked first time!!!
Gavin - as a note, when we did the reset thing, it also reset a config entry for the wifi mode. A small change in the config.ini (original!) and it's all better :)
Now I'm just trying to figure out how I can use the "customised" ardrone_autonomy package (from the tum_ardrone page) without overwriting the regular ardrone_autonomy package...