Cannot install on HP Pavilion

[Russell Murphy]

I'm trying to install FreeBSD 9.1 Release on an HP Pavilion Slimline (model s5-1414); I get through the installation fine, but when I re-boot, the machine gives an:

     ERROR: No boot disk has been detected or the disk has failed.

I looked around for suggestions via mailing list archives, google, and such but no luck (or perhaps the wrong search terms).

Details:

I've been using FreeBSD for more years than I care to admit (i.e. more than 10); I'm generally pretty familiar with the process and the installer, but am by no means an expert
The target machine is a model s5-1414, product # H3Y75AA#ABA
I went through the whole process: re0 configured using DHCP
	* guided partition; using the whole disk
              ada0
	         ada0p1	64kb	freebsd-boot
		 ada0p2	927GB	freebsd-ufs	/
		 ada0p3	4GB		freebsd-swap	none
	      commit = yes
	 * fetched distribution files (e.g. base, kernel, doc, games, ports, src)
	 * root password; setup user OK
on boot, the error (above) is generated
the BIOS is an HP/American Megatrends ver. 2.15.227
relevant (?) settings include:
    	 * Storage:
	      SATA Emulation: AHCI
	      Boot Order:
	         (I've tried just about everything), but
		 the relevant part seems to be that the Legacy devices never "work"
          * Security:
	      Legacy: enable
	      Secure boot: disable
	      Fast boot: disable

Please let me know if there's anything else you would care to know or see. Any ideas or suggestions?  

(Forgive the email formatting, it's a combination of xemacs and my Mac laptop…).

Thanks-

Russ M.