yaboot freezes when "boot from CD" function is selected

Summary: Yaboot bootloader freezes when "boot from CD" function is selected.

Steps to reproduce:
1. boot from CD into the bootloader.
2. Sometimes, this eventually boots the CD

Results:
Freeze from which you sometimes get released by waiting it out, although control-alt will sometimes get you into terminal (to pass "reboot") but probably doesn't break the freeze.

Expected Results:
I expect to boot from the CD to start smoothly.

Circumvention:
Select the C key immediately after the power-on chime, and avoid the bootloader entirely.

Hardware:
400 Mhz slot loading iMac DV
Jaunty alternate and desktop CDs