You can always try it... Its cheap enough for the second one that you won't cry too much if it doesn't work. Much more and you are better off looking at the external USB style video I mentioned earlier.
Personally I like the USB video adapter more than an isolation transformer but that will be your call about which you feel more comfortable with. At this point I wouldn't spend much money on anything like this unless you can return it.
You have a composite video input? I thought it was mentioned you had VGA...
You may be interested in this thread I just found as well: