Connecting G5 with Sony Trinitron Only---Problems

I am running MediaCentral on my Powermac G5 to turn it into a media center. All I want to do is connect my Sony Trinitron to the G5. I bought the comosite/S-Video adapter from Apple. However, when I plug in my TV, I get absolutely no picture on the screen. I can tell that there is a signal because the lines begin moving on the TV. I know the card is fine because I can plug it into a regular monitor and everything works great. I, of course, can't adjust any settings because things change when you plug in the different monitors. Does anyone know how I can get the display to show up on the television?

Video Card: Radeon 9650XT
System: 2.0 X2 G5
Monitor: 27" Sony Wega Trinitron
OS: 10.4.8