Rafael,
Sorry for the late reply. I ended up going back to Windows for now, as I couldn't get the XDS100 driver to work under Ubuntu. When I plug in the XDS100, I only see one device populated (/dev/ttyUSB0).
I did check the udev rules and they are installed properly, and everything was installed with superuser privileges.
If I get another opportunity I will try to figure out why the USB driver isn't loading properly, as I would prefer to use Ubuntu.