Ok, I just installed an Onkyo TX-SR620 Receiver and an Onkyo DX-C390 DVD changer in a small living room. I programmed a Pronto TSU3000 to run the small setup. At first everything seemed to work fine. But, I've run into one small problem. When the DVD input is selected on the receiver, the Pronto is no longer able to control the Receiver or the DVD player. No functions on either device work. The other devices (RCA TV, Lights, etc.) continue to function properly. If the receiver is changed to another source using the front panel buttons, everything works fine again. If the receiver is powered off everything works fine again.

What is causing these two devices to refuse ir commands from the Pronto when the DVD input is selected?

Just rambling here, really, and not presenting ideas in the order I would try them....

I really loved it when I worked for a corporation and my boss would tell me to find out why. It took a week sometimes. Ah, well, I just can't afford to do that today. That is a preface for my rather cavalier-sounding "Who the hell cares why?"

Use another video input and see if that solves the problem. Heck, maybe the DVD player is putting out IR for some dumb reason, and it won't matter WHAT you hook it to because that IR interferes with the remote!

Try this same process with the DVD player unplugged to be sure it is not mucking things up.

Are you using RF or IR?

But wait, you said all is well after powering down the receiver! Try changing the input setting on the receiver, say to ANALOG, or even 6 CHANNEL, even though that is not what you want, to see if that affects things. Maybe there is something wrong with the receiver and some kind of oscillation happens when you switch it to DVD AUTO, that somehow interferes with the IR system.

In short, try everything that makes no sense but that is different. After all, you have a problem that makes no sense but is different, so those are the things you should manipulate.

Is it possible that it uses a different set of IR commands when DVD is selected? Try learning a code or two when it is in DVD mode and see if they work.