I spent a few minutes rebooting a few times wondering why I kept starting with the default BootX kernel. I would suggest something along the following to be included in the docs, after the YaBoot section, or create a separate section/step for BootX: BootX users enter the BootX control panel, select Options, and uncheck the "Used specified RAM disk." When you return to the BootX main screen, you will now find an option to specify you root disk and partition. Specify the partition to use your new Gentoo linux installation.
fixed in cvs.