Post-install problems w/FC5 on Sun Fire x4200

[David Nedrow <dnedrow usa net>]

I've run into a really odd problem installing FC5 on a Sun Fire x4200.

The 4200 is a dual AMD64 with an SAS RAID controller (SAS1064) from LSI.

The RAID controller has four drives configured as two logical,  
mirrored volumes.

The FC5 installation goes without a hitch, but after rebooting I  
never get a grub display.

I've tried installing grub to both the MBR and the boot partition  
with no difference.

If I don't configure logical volumes on the RAID controller, FC5  
installs and boots without a problem.

Has anyone successfully installed FC5 on an x4200 with mirrored drives?

Any tips would be appreciated.

-David