Ok, so for Christmas I got a Harmony 360 controller so that I wouldn't have to deal with flipping between 5 remotes.

So yesterday I click on the 'play xbox360' button, which is supposed to turn on the TV/xbox/receiver and put them all on the correct input. It's been working fine for the last few days, but yesterday when I did it - something wierd happened.

The screen was black, with a few white lines streaking across it. Everything was on, and they were on the correct input too. I switched it back to 'watch tv' and then back to 'play xbox360' and everything was ok.

My question is: What could have made the screen appear like that?

It could be that the tv didn't receive the entire signal from your remote for some reason and ended up on the wrong setting for viewing Xbox. Happens sometimes with longer macros or if your hand wobbles too much when it is sending the signals.

It may have failed to sync up with the HD signal from the Xbox. This system is more like a computer than the NTSC system. If you've ever had to turn your monitor off/on with your PC to get a pic, you've seen the same thing. People have all sorts of problems with syncing some displays with some sources.

Sometimes it's just timing. Maybe your remote macro should do the commands in a certain order to make sure the Xbox syncs properly the first time, like turning the Xbox on sooner in the sequence.