There is a workaroud that I have found to be working flawlessly.

1. Change the power on setting from "power" to "power and numeric"
2. Turn on the Box with: '0', delay, 'exit'
3. Turn off the Box with: '0', delay, 'power' (The box will always power on before it turns off)

Works on most Scientific Atlanta boxes. The cable provider could have removed that setting.

Good luck.