I just got xUbuntu (Live CD) fully working on my softmodded Xbox.
I burned the iso to an Office Depot CD-R/W, since the TDK CD-R/W I started with didn't read well at all on my Samsung drive. I also bought a wireless USB keyboard & mouse made by Micro Innovations at Wal-mart for $30, both of which were recognized in xUbuntu (I understand that many mice for such combos aren't). I logged-in using "live" as the logon AND password. The main & final problem I had to correct was getting Firefox to go out to the Internet. I had the right settings for my Xbox's IP address and Gateway that xUbuntu uses by default, but the DNS wasn't set to the correct address of my router (192.168.0.2). After some digging, I found that the DNS address is saved in a file under "/etc/resolv.conf", which I was able to locate. I was able to edit it with the text editor in-cluded with xUbuntu and surprisingly was also able to save these changes (changed "192.168.64.1" to "192.168.0.2"). I presume this file was saved to the Z-partition, which I understand is also used for the swap file. However, I suppose I may need to repeat this process the next time I boot up using my Live CD. I was also very limited in the type of pages that could be pulled-up, restricted mostly to simple Google searches (although Google image searches could also be pulled-up fine). I noticed that the <y> & <z> keys were reversed too, which I think is most likely because this is the standard German keyboard layout. For some further/related info., refer to the following link: http://www.xbox-linux.org/wiki/XUbuntu