Chuck,
I endorse Dwayne's recommendation that you first switch to the latest Ubuntu. If you do not have the bandwidth to download it, ping me and I will mail you a CD. You are really going through way more trouble than you should.
Second, you should probably just use your onboard Ethernet (eth0) rather than the whatever godforsaken OEM PoS card that your DSL provider gave you!
Third, I think we are sort of pissing around in the wind and not being methodical about this at all. Unless of course you are confident enough about this stuff i.e., don't let me be a scold. First we need to understand your topology and gear. You have a single PC which has a wired twisted pair ethernet connection to a carrier supplied DSL modem. Is that right? Can you tell us what the make/model of the DSL modem is? When you are in XP mode, can you access the modem's web admin interface?
Send me off-list email with your phone #, if that might help, so that we can work together.
Cheers,
--ravi