Computer buffs needed

Right then.

I want to play videos etc. on my pc but watch them downstairs on my Tv. I bought a wireless sender unit with s-video input ability (via connector) and the picture was perfect apart from white lines going up the screen every 2 secs and a loud craking noise with every line. I removed any interference by putting the transmitter and reciever next to each other in the same room and still got the annoying lines.

SO..i took it back and bought a 15m s-video cable and 10m stereo to 3.5mm jack lead instead...now i can get the sound pefectly but no picture.

The CPU (fujitsu siemens with 400GB hard-drive & 1 GB RAM) has an ATI video card with video in-out ability via a 7 pin s-video female (and 4 lead adapter..tulip in/out..s-video in/out)...
The TV has a 4 pin s-video in female...
the s-video cable is 4 pin twin male.

I can make it work with the tulip connector but i can only get my hands on a 2m cable and it has to go 10M

Any ideas why it won't work with the s-video???? Do i need to convert the signal to composite ???

I'm gonna run cry soon