Ok, putting it in the DMZ was a good idea.
Your router will pick up the ISP's DHCP ip address, but you have assigned your Router a LAN ip address. Default it is 192.168.1.1.. 192.168.0.x is a different subnet which would make it not work. Double check your ip address scheme, in the worst case change that 0 to a 1 and reassign all of your ip addresses. Double check your PC with the FTP server on it and make sure you have it set up statically with the 192.168.0.40 address.