So, desiring to play both PS3 and 360 in HD, I invested in an AV switch. I hooked it up, everything seemed to be going fine. My PS3 runs like a dream with the new component cables I purchased, the games look better then ever. My Xbox 360, however, is a different story.
First, on the games menu and Xbox Live menu, the bottom half of the screen goes berserk. I can't see anything. I was able to navigate, and started up the Too Human demo. The character select screen constantly shakes, and during cutscenes I get blackouts. I tried changing the resolution, but 1080i is the only setting that works properly.
Anyone have any idea what the problem is?

I would say call Xbox support but they suck. I think the problem might be the AV switch

Hmm... I had that issue going to 1080p. It's definitely not cooperating very well with the AV switch so I don't know what to say except that your Xbox is a very needy piece of technology.

Too much awesomeness pouring into one AV switch?

My xbox displayed mad weird with a VGA cable, there was so much blank space on my dashboard it was weird.

I'm using the component connections that came with it.
So far, I've tried the Xbox forums, but those guys are useless. The only person who didn't ignore me was a guy who treated me as if I was a complete idiot.

Now I assume the AV switch is just a basic HUB for all your AV cables, and the HUB plugs into the TV? If so, did you try removing the AV switch and plugging your 360 directly into the TV again? Either that or I'm thinking of a different device.

Yeah, it is basically a hub. Having it plugged directly into the TV was previously how I had it set up, before I got the PS3. Back then, the only problem I had ever had was when the startup screen for Ikaruga was all shaky. Now, it is in nearly every game.