I am also having a problem with UWO RezNet, however I am using Arch Linux (this installation worked fine back home). Interestingly enough, I used to Reznet last year as well, and I didn't have any problems even with defaults setting given by many LiveCDs. This year, neither my Arch Linux nor any liveCDs I tried work..
Looking at RezNet guidebook (following instructions for Mac, to be precise), I also set my account name as DHCP client ID, and set uwo.ca as my hostname, but still it is not working. I did register my network card using my windows Vista though, so maybe that is why. But the it didn't cause problems last year. (and BTW, you have to register your network card at registerme.uwo.ca before using internet, but I imagine you've already done that). I've emailed reznet staff, but so far I am getting no reply. I am afraid that I have to call them sometimes next week, it is frustrating....