Your TV does not support HDTV resolutions. (480p, 720p, 1080i)
You can only use normal resolution on your TV. (480i)
Component cables support 480i just fine, just make sure ALL the HDTV options in the Microsoft Dashboard are turned off.
NOTE: Yes, the picture is supposed to look better with component cables. BUT, you are currently running in 480p (HDTV) and your TV does not support it, which is why it shows a double picture. Disable all resolutions in your Microsoft Dashboard and you will be fine.

Cool thanks for the input. Ya, I figured it was the TV, it's an Olevia LCD that's over 5 years old. We just got a new 50" Panasonic plasma downstairs so I'll try that one when I get home. I was just being lazy and didn't want to bring my xbox downstairs.