If Power Tracking is turned on for a given device, each POWER TOGGLE command flips the active state for that device. The Tracking option is set on the Device screen for each device – note that the option is only presented if the device is in fact a toggle device.
Any usage of POWER TOGGLE to such a device from an Activity command list or a button on a Remote Design will flip the current state of the device. Note that using a Test Remote or Manual Remote does *not* change the current state of the device – using one of those is how you fix the "but I pushed the button on the front of the device" problem.
When sending commands from an Activity Command List, POWER TOGGLE is then only sent when appropriate. If Roomie knows a device is currently on and you hit System Off, the command goes through. If we know it's already off, it doesn't. The same applies vice versa to situations where the device is being turned on.