Thanks for all that Harry,
Yes there is only one computer and as far as i know there is only one ethernet (on the motherboard) (i know i should know if i've put in another network card in my own computer, but i cant remember if i did when i built this one, Ill check when i get home)

I'll have a go with ethereal and changing the ip adresses and let you know how i get on.
Thanks again for your help.