Need help with Soft15k sync problem

[jimmy2x2x]

Hi, I have hacked a VGA to SCART cable together and I am experiencing sync issues with soft15k

Windows xp sp3
GeForce 6200 AGP with 197.45 WHQL drivers
Panasonic Quintrix RGB capable TV (confirmed 50/60hz)

I have installed soft15 with 15khz options only, set the resolution to 640x480 then rebooted

When I change the res with quickres, my LCD goes out of range (as expected) I switch over to the TV and the picture isnt synced at all on most resolutions, however I can almost get a stable image with a res of 288 vertical (512x288 for example) These resolutions have a solid horizontal sync, but scroll up the screen.

Any ideas on what the problem can be?

Thanks