Freebsd failure to boot from CD on HO Pavillion ze4600

[scion+fbsdq at webrelay.net]

Greetings,

I've got an HP Pavillion ze4610us laptop.  I've burned a number
of FreeBSD 5 (and FreeSBIE 1.1) images to cd, and have had no
luck getting this system to boot from them.  The same images
boot on other systems, and the laptop in question boots WinXP
CDs just fine.

I'm stumped, and nearly ready to punt the whole deal, but thought
I'd ask if anyone has seen similar behavior and figured out what
to do about it.  

Behavior is that after the boot rom splash (the hp/invent logo),
the cdrom spins mightily, the cdrom light emits the barest of
flickers, and the system proceeds to attempt PXE.

Cheers!
-sam