I had the same issue with my wife's compaq LT tring to use the DVD player on my folks' TV. The laptop detects the monitor connected to the SV output, but doesn't display on it. What I was able to do was use the TV as a second monitor to extend the viewing area. If you go to display - settings you see the monitor layout in the window. In my case the second monitor automatically became active when the SV connection was made. I was able to initate an application on the LT display and then drag it to the TV and maximize to fill the TV screen.
