Thanks mate! I'll try it later today.
It seems the problem I am encountering is different from the one in this thread.
What is happening in my case is that, when the power button command is set to "suspend", after pressing the button Kodi powers off but doesn't send the CEC command to the TV and Receiver. Upon waking the system, the command to turn off the TV and receiver is sent followed shortly by the command to wake.
So the behavior is as follows:
Kodi On --> Press Power --> System Powers down, TV and receiver remain on --> Press Power --> PC Powers On --> TV and receiver power off --> TV and receiver power back on immediately.
I suppose I should open a separate thread on this.