Is the video blurred horizontally? If so, then your cables may have too much capacitance and loss for your S-video output. Make sure you're using low capacitance, low loss shielded cable. At least RG-59 for both signals.
Also make sure your load, the device you're delivering the S-Video signals to, has termination resistors across the inputs. These should be 75 ohms. You may have to patch these in on your own.
Coax lines need to be properly impedance matched when they are long. Short cables don't have time to mess up the video signal, so they tend to use any old cheap coax or even dumb twisted pairs.
Be wary of cables that are super flexible, that suppleness usually means tiny wires inside and that means less signal strength the longer the cable.
Fav quote - "Experience is whatcha don't get 'till ya don't need it no more."
System - Athlon 1.4GHz, Win98, Hauppauge PVR250 receiver and compressor.
Software -Magix Movie Edit Pro 10, Nero 6 + NeroVision Express, Moho 4.61, PSP 8.1, Bryce, Quicktime 6.52 pro, Goldwave 5, DVD-Lab.
Cameras - Panasonic GS9, Canon ES8400V, Canon EOS D20 and Canon A70