I understand, it is just not possible.
as i said your image needs to be exactly the same size as the slider container, otherwise there are no hacks or any methods to make that frame perfectly fit the container, because the frame is small and the container is bigger.
maybe if we cut the image in half and then with css set each one on each sides of the container, thats the only css method i could help with.
if you want it, cut the image in half and attach it in your reply, i will try to do some css hacking for you lol