I'm sorry to hear that you're having this issue.
Would you post a picture on www.imageshack.us and post the link here so I can see what you're describing?
I just got the LN46C670 and it works great. However, when I select the screen fit mode there is a 2 inch white line on the top right of the screen. I position the screen so it disappears but when I change between sources or turn the tv off it resets. Is this a firmware issue? I just don't want to sacrifice quality by using 16:9. I also made sure its on home use mode.