5.2.1-RELEASE boot problem

[10,000 Screaming Monkeys]

I know I'm going to regret asking this, because it's undoubtedly
something simple that I'm missing, but I can't for the life of me make
this work.

A little background: I have FreeBSD 5.2.1-RELEASE installed on an ATA133
drive, which is connected to a Soyo SY-P4S Dragon Ultra motherboard. The
motherboard has 4 onboard IDE ports -- two regular (slower) IDE ports
(labeled 1 & 2 on the board), controlled by the BIOS; and two faster
"RAID" ports (3 & 4), controlled by an onboard Highpoint HPT370/372
controller.

When installing from CD, everything works as expected with no errors,
regardless of which IDE channel/port I have the hard drive connected to.
And, just to note, when I have it connected to IDE port 3 (an
ATA133-capable port), FreeBSD addressed the drive as ad4 after booting.

When attempting to boot after the install, however, the boot loader is
apparently defaulting to a floppy drive, as this is all I get:

	Verifying DMI Pool Data ............
	error 1 lba 0
	error 1 lba 0
	No /boot/loader

	FreeBSD/i386 boot  
	Default: 22:fd(22,a)/kernel
	boot:

If I type "0:ad(0,a)/boot/loader" at the boot: prompt, though, it
actually runs the loader and presents me with the ASCII daemon and the
boot menu.

I've tried putting that "0:ad" statement in /boot.config, but it didn't
seem to have any effect on the boot process (i.e., it still defaulted to
22:fd and gave me the same errors).

Can anybody tell me what I might have missed, or what I might be doing
wrong? My head is getting a little sore from beating it on random hard,
flat surfaces.

TIA,
Jamie