2 machine p2p LAN network not working

I have the two machines which i have been working on for the past two weeks fully repaired and rarin to go. Problem is, the small 2 machine direct connection network that i have made refuses to connect the two machines to each other. I am using no router or hub. The master machine is the one with the wireless acess and i want to rig my little network up so that both computers are connected to each other and the internet. I wont reveal the IP adresses for safety reasons (although my custom made AV and AS programs handle pretty much everything that goes my way) Is there anything i can do to make this network run? (P.S. The crossover cable is a normal networking cable that i modified to be a crossover cable. The cabe DOES work though because as soon as the connection was made both computers tried to connect to each other but they say that the IP adresses on both are identical [this is possible because the slave machine is running a cloned copy of windows XP])