I was going to install Ubuntu on my Dell Desktop (n-Series) at work. So, I burned a CD, fired it up, and...the setup crashed to BusyBox with errors about the ata device. I had seen this before. It had been a while, but I had seen it before. A few minutes of irritated googling later, came up with the following steps:

  1. boot to the live CD
  2. add these options to the kernel line (press F6 to get there):
  3. Because of my dual head setup, it was also easier to boot into safe graphics mode

This allowed me to run setup and get Ubuntu installed...and I shouldn't even have to mess with it.