Right, Found the issue.
The s-video on the 9250 is exactly as above and that is the issue the vp-p is too low on this card. Last night i installed a Nvidia FX 5200 129 pci and VOILA!!! it is now outputing via S-Video. So dont use a Radeon 9250 and to be honest i was a bit stupid using an ati over an nvidia anyway......my bad.
I have however got a further prob which i have had before with my normal house tv. The svideo is rather fuzzy/blurry, what i , mean is that it is not very defined so it makes navigating windows very painful. Although anything that is media centre like is ok as it is meant for this sort of application. I do run Autoroute on the pc aswell for gps and general mapping and this is a definate no go as you cant see ****!!!!
Anyone have any ideas about getting round this? The only alternaticve is to get me self an XGA/SVGA tft touchscreen.