I had a recording scheduled on Ch4 last night, and my wife concerned I might not have set it up, asked my daughter to also record the same programme. The result is we have two recordings listed, but neither will play. Is there any way of retrieving either recording?

It shouldn't normally be possible to set something to record twice but it can happen, particularly if using Series Link. Are there are any symbols against the recordings in the Play List? Was anything else set to record at the same time? The other possibility is that you are seeing the starting signs of file system corruption.