Laptop network problem

I am having serious problems getting my laptop and home desktop to talk to each other. Both machines are running XP. I have allocated the IP addresses 192.168.0.1 & 192.168.0.2 and the subnet masks 255.255.255.0. I have also ensured that they are members on the same workgroup but they still refuse to see each other. I am using a direct cable (cross over RJ45) to link the machines, which has worked OK in the past. I am sorry to ask such a stupid question but it’s driving me insane! What other settings should I consider/change – Any advice would be greatly appreciated!