freeBSD 4.9 won't boot after installation

[estate]

HI,

I am pretty sure this is a misconfigured partition problem but maybe someone there can help.

installing freeBSD 4.9 onto a compaq deskpro, 4 GB IDE, 192 MB RAM, previous OS is XP home ed.

I dedicated a 4 GB drive to freebsd 4.9 and specified it be bootable. I also installed (at least
once) the boot loader.

no matter the configuration when the boot loader or the bios tries to boot freeBSD  a black, blank
screen appears and the system reboots. It loops like this.

no problems installing from CDrom. Only problem is after the installation. I have confirmed that
freeBSD files are on the hard drive and as a test I installed SUSE linux onto the same machine, no
problems.

any suggestions or resources to explore. i have looked over the handbooks and googled it to death.

thanks very much

matt