Not to worry....found it myself

The latest Azur unit remotes utilise discrete on/off commands for multi room and custom install use. This means that the commands for on and off are on different frequencies, and will need to be learnt to seperate buttons on a learning remote control. To do this, press and hold down the power button on the remote control. After 12 seconds it will send the on command, and after another 12 seconds, it will send the off command.
When sending a signal from the remote directly to the device, this button will function as normal, and only needs to be pressed once to turn the unit either on or off.