No, i usually use the component cable for my xbox 360. I just testing the hdmi cable i usually use for my ps3 on my xbox 360. Hmm, i'm only have one hdmi cable for now, and it mostly working on my ps3.
Here's an update, after firing up Rayman 3 HD (which turned out to be just a trial) my ps3 change the resolution from HD to SD for whatever reason. So i exit the game, black screen, restart the console and restart the display back to SD, my ps3 notice the hdmi cable, go to display setting, i pick the custom setting, check the 1080p, black screen and it goes back to sd resolution. However, when i check the 720 and/or 1080i, the display output is back to HD or maybe HD ready.
This is weird because before i play Rayman, the display setting is 1080p.