problem booting 5.3STABLE from USB2 flash drive

[Jeff Stockett]

Hello,

I'm hoping to use freebsd as a custom router.  To minimize noise and failure 
points, I was hoping to boot from a USB2 flash stick which have gotten dirt 
cheap.  I downloaded 5.3RELEASE-i386-miniinst.iso and burned it to CD - 
stuck my 512MB flash drive into a USB port, and let the CD boot up.  
Everything appears to work, in that the installer lets me partition and 
format device da0 fine as well as copy over all the files (doing a "minimal" 
base install), but after it finishes everything and goes to reboot, the 
machine just hangs.  After a hard reset, at boot time I get:

F1 FreeBSD
Default: F1

but then the box just hangs there locked up tight as a drum.

If instead of choosing the "boot loader" option during install, I choose the 
standard "MBR" option after reset, I get:

No Operating System

Seems that the boot loader option almost works - but not quite.  Does anyone 
know what might be wrong.  Possibly some sort of USB initialize timing 
problem with the kernel?

FWIW, the board boots DOS fine off the USB key, so I know the BIOS/board are 
working as intended.  Thoughts?

Thanks,  Jeff