I have a Lemur Ultrathin laptop from System76. Today I tried to perform a fresh install of Ubuntu 10.04. After backing up all my files, I rebooted, pressed F2, and changed the boot order so that the USB CDROM drive was first in order. I then booted the Ubuntu 10.04 desktop CD from the external drive (a Samsung USB CDROM which System76 sent me along with the Lemur). I chose the option to erase the entire hard disk and replace it with Ubuntu 10.04. The install proceeded only until about the progress meter read about 5%, then the window disappeared and I was faced with a blank screen with the purple Ubuntu wallpaper, a mouse cursor and nothing more. I tried this a couple of times with the exact same result. So now I'm stuck - my machine is unbootable and I have no way to install 10.04 as far as I can tell. What can I do?