I have exactly the same problem, and have tried everything to stop her. It is driving me crazy because it happens everyday, sometimes 2 or 3 times a day. I have done the sleeping bag, nappy on backwards, buttons, pins, clothes on back to front, and the duct tape, both her nappy and then the clothes on top, nothing works. She still manages to get the tape off. Then when i go to put her clothes and nappy back on she does a runner. It doesn't help my sanity either that I have 3 year old twins who are being toilet trained and who also like being naked. Can ANYONE help or offer some advice.