I have had to replace the hard drive in a Mac iBook G3 that I was working on, and was trying to reinstall Mac OS X 10.4.6. However, the disk refused to load correctly (possible CD drive error, as I know the Mac disk to be good), and I also decided that it might be easier just to install Ubuntu from a flash drive. I have tried booting from a flash drive at the start up; as well as trying a variety of commands under the open firmware option, even going so far as to add USB boot options under the boot-device string, none of which worked. Two consistent error report I get are LOAD-SIZE is too small, and STACK UNDERFLOW. I would like to if there is a command to install Ubuntu from a flash drive.