Problem with Vizio 1080i? Lines seen crossing screen playing Halo 3?

[mr_america_117]

I set my buddies 37" Vizio (the high-end model with part silver finish) to 1080i when playing Xbox 360. I was playing the opening scene and you could see the lines scanning the television in the dark areas. I know this isn't normal, is it a bad set?

I was just wondering what was going on because I was planning on buying a Vizio this summer...

Thanks!