Ok, so my problem is I'm on HDMI with my Xbox. When I'm on the dashboard, streaming videos/music, doing pretty much anything, the audio is perfectly fine. But as soon as I put in a DVD to watch a movie, the audio cuts out. Does anyone have any clue as to why that may be? I have an Xbox 360 S if that helps at all.

Care to give any more detail on your setup? HDMI directly to tv or is there a receiver somewhere in the mix? Also, have you checked the volume settings in the dvd app. I'm pretty sure you can adjust volume/mute within the dvd menu.

Well, my setup is just an HDMI straight to my TV, which is a Samsung LCD, and then I also have a POS surround sound system, but it gets the job done. And it's not the surround sound either, because I was having this problem before I hooked it up. Oh, to use the surround sound, I just have a Red/White 2 ended audio cable that I connect to the audio out on my TV, then I connect that to my system.

When you say the DVD app, do you mean while the DVD is playing?

Okay, nevermind y'all. I just stuck in a DVD to see if I could change the volume and mute while it was playing, and it started to work. I even unhooked my surround sound to see if maybe that had changed it and caused it to start working, but nope. The audio was still there. Thanks for the attempted help though.