The good news is that I've got it working now. I found that the order you connect it matters. You have to power up the Klangbox and then connect the USB to the iPad connection kit. You then have to make sure the Midi Designer software is closed on the iPad and not running in memory, then launch Midi Designer and hey presto, it works. I'll put some screenshots up of the app that originally came with the Klangbox, which is fiddly to use and requires a PC, against my Midi Designer layouts. Thanks for all your help.