A/V TV-Output forced 4:3?

Ok, the issue is:

I have a system with a Radeon 9600 trying to output widescreen to a Sony Trinitron Widescreen TV (Dont know the model sadly) via S-Video. Is this possible because if it is for the life of me I cant figure it out.
If I run a wide-screen res all that happens is it pans over a 4:3 image.

Am I forced to use 4:3 over S-Video or is there something ive missed?

Oh and ATI CCC says the TV's max res is 1024x768

 

You're only really going to get 640x480 with s-video.

 

Within the video adapter properties, go to the overlay settings tab. There should be a Theater mode options button - set that option to theater mode and then the 16:9 option is available.

 

Thanks for the advice gman, sadly though it wont work as the one and only primary display on the system is the TV and for some reason theatre mode only works if the TV is a secondary or "clone" display. Also in Catalyst Control Centre it appears the options may have changed.

::EDIT::

Ok, seems 848x480 seems to work quite well so long as I put it in over-scan, only trouble with this is text is totally un-readable on the TV and I do miss and VERY small amount of the image from the left and right as when in Over-scan the ATI control pannel seems to disable image re-sizing.