I had the same problem with my Panasonic 50" G10. If you have the comcast box you can eliminate the green line by going in to the menu system of the comcast box and change the settings to RGB. This should get rid of the greenline. The procedure to get to the menu is to turn the box off then hit menu. This will bring up the adjustment area for the box. It works!
Does anyone else have a green line on the right side of the tv in either "THX mode" or when you go into advanced picture menu in the picture settings and set it to "SIZE 2"?