Also by default, your XBox 360 power configuration is set to use the power toggle method. Check if your XBox 360 device supports the discrete PowerOn/Off commands in device mode. If so, then reconfigure its power settings to use the discrete method (instead of the toggle method).

Note: The "number of repeats" (now nameless) setting is under Device > Troubleshoot > Show me more problems > Device doesn't appear to receive every command correctly > The device responds to some commands occasionally...