I suspect that the receiver doesn't have a toggle on-off, only discrete on & off.

I have a new Integra (made by Onkyo) receiver and DVD player. Strangely, the DVD player only has toggle on & off, the receiver only has discrete on & off. The reciever remote also knows how to control the DVD. Needless to say, when using the receiver remote on the receiver, the ON and STANDBY buttons work discretely. When using the receiver remote on the DVD, only the ON button works, and it functions as a toggle. The STANDBY button won't do anything to the DVD. Also suspicious: the power button on my universal remote (OFA Home Producer 8) will only turn the receiver on, not off. I suspect that in later models, Onkyo took the existing on-off toggle and turned it into a discrete ON, then added a new code for discrete off.

Why would you want a toggle on & off? Most people rejoice when they find they have known discrete codes. It makes macro programming so much easier.