VGA cable on HDTV

I'm using a standard VGA cable (which I originally purchased to connect my Dreamcast to my monitor), anyway I'm now using the cable to transfer my PC's image over to the TV as my existing monitor cable is too short. The TV is a Sony HD Rear-projection TV (720p), if that's important, although when the PC's image is up on the TV's screen, it has a slightly wobbly picture (which is hardly noticeable during moving images such as a game, but I'd rather it not be there).

My question is, would an SVGA cable eliminate this problem? I want to know as it will cost me another 20-30 pounds just to try it and I'm sure someone on here knows the answer.

Thanks in advance.