D408SR problem - trains go wild
I have a problem with a couple of locos where I have recently installed new NCE D408SR decoders. Occasionally, at the exact same time, they will both come into action, either running away at full speed or jerking along the track erratically. It doesn't happen with any other locos, which use a mixture of D408SR and Zimo decoders. I have an old NCE controller which has worked perfectly for years.
Has anyone else seen anything like this?