I just bought a new HD tv and I am very happy with it but many times on the HD net channel the tv shows a thin black line vertically on the left side of the screen. The line gets smaller or bigger depending on the programing. Today while watching a nature show about tigers, I could hardly see it but a sport show came after that and the black line became bigger than ever of about an inch. Has anybody had this problem?. dvds always fill out the whole screen and look great.