Shaw Assigning Different Subnets

Here's an annoying problem for you: two computers in a house, connected through a hub to Shaw Cable Internet. Now try ftping. I've come across this problem earlier this month, and it's back to haunt me today. As it turns out, Shaw's DHCP servers aren't smart enough to assign the same IP subnet to all computers registering through the same cable modem (I am entitled to two public IP addresses). When I try to transfer files over ftp all communications have to go through Shaw's router because they are on different subnets. This means that all transfers are limited to 50KBps, and the transfers will count against me in my monthly upload/downloads. One way I have found around this is to set IP aliases on both machines, creating my own private network (10.x.x.x). Of course, Windows needs to be rebooted every time you fart, so I have to wait for Kevin to save his game of Rollercoaster Tycoon so that I can restart the machine and get my own private network running in parallel. Oh, and this method seems to break the simple domain names that Shaw uses (like "shawmail" for my pop3/smtp server). Do I fiddle around with my DNS and gateway settings (breaking any hope of proper DHCP), or do I reboot Windows twice every time I want to transfer files? I've emailed Shaw technical, and the guy basically said that IP address allocation is handled by the DHCP server so they have no manual control over it.