I am trying to install Debian 3.1r2 or Ubuntu 5.10 on a clamshell iBook
G3, but the CD will not boot. The existing Mac OS (9.2) reports an
error showing that the CD is DOS-formatted, and when the machine is
rebooted the CD-ROM drive does a quick drive seek (I'm guessing by the
sound), and then continues to boot into OS 9. Has anyone had a similar
issue or advice as to how to correct this?

Thanks.