Windows Remote Desktop Procedure not working

Question

I have two computers both with Windows XP SP3 Pro and two network cards. Everything it's linked as described below:

1. PC named A, has 1 expansion network card Intel Pro 1000 with IP set to 10.0.0.1 used to control a camera. This cannot be changed.
2. PC named A uses motherboard network card Intel Pro 100 to communicate with PC B. This IP is set to 192.168.151.2 smask 255.255.255.0.
3. PC Named B has mobo network card Atheros to link with LAN. This IP is set to 192.168.100.53 smask 255.255.255.0.
4. PC Named B has expansion network card Intel Pro 1000 used to communicate with PC A.

A and B are linked by a crossed cable, firewalling is disabled and antivirus too. We're connecting to B by TW and from there to A by RDP, but since today it's impossible to get the stuff work. If we change IPs (we already switched from 20.1.1.1 to 172.16.0.1 and to 192.168.151.1) we get the RDP work again until we shut off the computer, then once rebooted, we're unable to connect again. When we tested computers here, everything was fine as almost well as we took them to customer. I'm thinking that it's a hardware question ( different card speed 100-1000, bad wire, bad card? ), but am I missing something software?