Can't detect 16:9 (wideacreen) aspect rato

I have an LG RH7823W DVD recorder, connected to an LG plasma TV. On the recorder setup menu, I have selected the display as 16:9 ratio. I have also selected the "aspect ratio auto detect" option on the TV. I have the equipment connected via component video and optical audio leads. But when I turn the dvd on, it always displays all menus and movies in the 4:3 aspect ratio, even the dvds recorded in 16:9. The auto detect function works fine on digital TV, but not on the DVD recorder. Can anybody please help?